The Jewish Museum Vienna and the Austrian-Israeli Society were among the possible targets of an alleged Hamas network that investigators say was preparing attacks in Europe around the second anniversary of the Oct. 7, 2023, Hamas-led attack on Israel, according to a joint investigation by Germany’s Der Spiegel and Austria’s Der Standard.
The investigation, published this week, provides new details about an alleged plot that European authorities disrupted last year, including the possible involvement of senior Hamas official Basem Naim and communications with his son, Mohammed, whom investigators have identified as a central figure in the network.
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A suspected Hamas member arrested in Germany over an alleged plot to attack Jews
(Photo: REUTERS/Heiko Becker)
German federal prosecutors last month indicted seven suspected Hamas members, alleging they were involved in acquiring weapons and preparing an attack in Germany or Austria. Prosecutors say the network obtained 13 pistols, a fully automatic rifle and 718 rounds of ammunition as part of preparations for attacks against Israeli representatives, Jews or people considered supportive of Israel. Hamas has denied links to the suspects. tagesschau.de
Senior Hamas official’s son at center of investigation
According to Der Spiegel and Der Standard, Basem Naim, a member of Hamas’ political bureau and a former health minister in Gaza, allegedly discussed plans for attacks in Vienna or Germany with his son behind the scenes.
The two also communicated on Telegram about other matters, including ceasefire negotiations with Israel and U.S. policy, according to the investigation. The alleged conversations are notable because the elder Naim has publicly condemned attacks targeting Jews in Europe and the United States.
Basem Naim
(Photo: Ozan KOSE / AFP)
Investigators have pointed to another episode as evidence of the close relationship between father and son.
After an Israeli strike targeting Hamas leaders in Qatar in September 2025 put Basem Naim in danger, Mohammed made an unplanned trip to the Gulf state, according to the investigation. The trip came about a month after he had allegedly recorded a video in Vienna claiming responsibility in advance for the planned attack.
Der Standard said the trip indicated the close relationship between the two men, although investigators have not established publicly what they discussed during the meeting.
Mohammed Naim
Mohammed Naim had previously been linked to weapons recovered in Vienna. The latest investigation provides additional details about the video authorities say he recorded.
Late on Aug. 7, 2025, investigators say, Naim was filmed in a rented room in Vienna’s Favoriten district wearing a hat, covering his face and concealing his eyes behind sunglasses. Two pistols were placed on a table in front of him.
The recording lasted 4 minutes and 32 seconds.
In the video, according to the investigation, Naim spoke of taking revenge against Israel over what he called “genocide” in Gaza and warned that “blood will be spilled.” He also allegedly said the “armed resistance” would send Prime Minister Benjamin Netanyahu a “message in blood.”
Investigators later found traces linking Naim to weapons seized in Vienna, according to Der Standard. The two pistols displayed in the video are suspected of having been part of the same weapons shipment.
Guns hidden in Vienna storage unit
The joint investigation also provides new details about how the weapons were stored.
Five HS-9 pistols were allegedly hidden for weeks in a self-storage facility in Vienna’s seventh district. The unit had been rented under a false name and was located within roughly 1.5 to 2 kilometers of several Jewish and Israeli institutions, according to Der Standard.
Weapons and ammunition seized during the operation targeting the alleged Hamas network in Europe
The storage facility was also near major public transportation routes, potentially allowing people to arrive and leave quickly without attracting attention.
The pistols were hidden inside a suitcase lined with a thick layer of aluminum foil. Investigators also found gun-cleaning oil and lubricant used to maintain firearms.
Investigators viewed those items as an indication that the cache was not merely an emergency weapons stockpile but contained firearms being maintained for possible use, according to the report.
It remains unclear precisely what attack was planned for Oct. 7, 2025, who would have carried it out and which location would ultimately have been targeted. But the Jewish Museum Vienna and the Austrian-Israeli Society were among the sites investigators considered possible targets, Der Standard reported.
Mossad tip reportedly helped uncover network
The investigation also sheds new light on intelligence that helped German authorities identify the alleged network.
According to Der Spiegel and Der Standard, Israel’s Mossad intelligence agency provided Germany’s domestic intelligence service in June 2025 with information indicating that terrorism suspects were involved in weapons transactions in Germany.
German authorities subsequently placed members of the network under close surveillance as they traveled across Europe and acquired weapons and ammunition, the outlets reported.
The German government had previously declined to confirm or deny whether Mossad had provided such information, citing restrictions governing intelligence shared by foreign services.
13 pistols, an automatic rifle and seven defendants
The existence of the alleged network and preparations for an attack had previously been disclosed by German authorities.
Federal prosecutors say Hamas’ military wing, the Izz ad-Din al-Qassam Brigades, had been building weapons stockpiles in Europe before a concrete attack plan began taking shape by July 2025.
The attack was allegedly intended to take place around the second anniversary of the Oct. 7, 2023, attack, when Hamas-led terrorists killed about 1,200 people in southern Israel and abducted 251 others to Gaza, triggering the war in the enclave.
The potential targets included Israeli representatives, Jewish civilians and people or organizations identified as supportive of Israel, according to prosecutors. German media previously reported that Jewish institutions and pro-Israel demonstrations were also considered.
Prosecutors say the network ultimately acquired 13 pistols, a fully automatic rifle and 718 rounds of ammunition through two separate procurement operations.
In the first, five HS-9 pistols were transported by train from Copenhagen to Berlin in late July 2025. The weapons were then transferred through an intermediary to Mohammed Naim, who allegedly took them by train to Vienna and placed them in the storage unit.
Naim allegedly returned to Berlin in late August to obtain 100 rounds of ammunition for the pistols.
The second procurement effort also led to Denmark. A suspect identified as Borhan El-K., who investigators say had contacts in criminal circles, allegedly traveled to Germany in August 2025 to collect a fully automatic rifle, eight Glock pistols and more than 600 rounds of ammunition.
The weapons were moved through an intermediary to Berlin and were apparently intended to be hidden in Leipzig, according to the investigation.
German police intervened before that could happen.
On Oct. 1, 2025 — six days before the anniversary of the Hamas attack — authorities arrested three suspects during a weapons transfer and seized firearms and ammunition.
Additional arrests followed in Britain, Denmark, Cyprus and elsewhere in Europe. Nine suspects have been arrested in connection with the case, and seven have been indicted before a Berlin higher regional court. They hold German, Danish, Bulgarian and Lebanese citizenship.
The defendants face allegations including membership in a foreign terrorist organization, preparation of a serious act of violence threatening state security and firearms offenses. Some are also accused of violating German laws governing weapons of war. The court must still decide whether to open a trial on the charges.
German intelligence source among defendants
One of the most unusual aspects of the case involves a defendant identified as Mohammed S., a Lebanon-born Berlin resident who was simultaneously working as a source for Germany’s domestic intelligence agency, the Federal Office for the Protection of the Constitution, known by its German initials BfV.
He is accused of helping the network obtain ammunition without telling his intelligence handlers about his own involvement.
According to earlier German reporting, after members of the network lost part of their ammunition, Mohammed S. allegedly helped obtain 300 rounds for about 1,050 euros. He was arrested in January 2026.
The BfV has acknowledged that he was a source but said he was never instructed by the agency to participate in the alleged plot. The disclosure has prompted questions in Germany over how an intelligence source allegedly became involved in supplying ammunition to a suspected terrorist network.
A network years in the making
European investigators believe the infrastructure uncovered in 2025 grew out of a broader Hamas effort that began years earlier.
Investigations have linked Hamas operatives to a weapons cache established in Bulgaria as early as 2019, with members of another network attempting to locate weapons depots in Europe in 2023.
Four members of that earlier network were convicted in Berlin this year and sentenced to prison.
The latest case represents a potentially significant development in European authorities’ assessment of Hamas activity on the continent. European security officials have historically viewed Europe primarily as a base for fundraising, political activity and logistical support rather than a theater for Hamas attacks.
Recent investigations have raised concerns that this may be changing.
A study by the Combating Terrorism Center at the U.S. Military Academy at West Point concluded that Hamas had spent years developing weapons caches in Europe and preparing capabilities that could potentially support attacks outside Israel and the Palestinian territories.
In the network uncovered last year, German prosecutors allege those preparations had progressed considerably further: weapons were ready for use, firearms and ammunition were being moved across several European countries, possible targets were being considered and a video claiming responsibility had already been recorded.
For investigators, those elements are central to the case that the alleged network had moved beyond maintaining weapons for possible future use and was preparing for a specific attack.