Hackers targeted the website of the English language Jerusalem Post early Monday, replacing its content with an image that threatened a site associated with Israel's undeclared nuclear weapons program on the anniversary of the killing of a prominent Iranian general.
While no group immediately claimed responsibility, the image posted included a missile coming down from a fist bearing a ring long associated with Qassem Soleimani, the Iranian general killed by a U.S. drone strike in Iraq two years ago Monday.
The image included an exploding target from a recent Iranian military drill designed to look like the Shimon Peres Negev Nuclear Research Center near the city of Dimona.
The facility is reportedly, already home to decades-old underground laboratories that reprocess the reactor's spent rods to obtain weapons-grade plutonium for Israel's nuclear bomb program.
Under its policy of nuclear ambiguity, Israel neither confirms nor denies having atomic weapons.
In a tweet, the Jerusalem Post acknowledged being the target of hackers.
"We are aware of the apparent hacking of our website, alongside a direct threat to Israel," the newspaper wrote. "We are working to resolve the issue & thank readers for your patience and understanding."
There was no immediate response from the Israeli government. The hack comes after Israel's former military intelligence chief in late December publicly acknowledged his country was involved in Soleimani's killing.
Iran as well did not immediately acknowledge the hack early Monday. However, the country in recent days has stepped up its commemorations of the slain Revolutionary Guard general. Memorial services were scheduled to be held Monday marking his death.
As the head of the Quds, or Jerusalem, Force of the Revolutionary Guard, Soleimani led all of its expeditionary forces and frequently shuttled between Iraq, Lebanon and Syria. Quds Force members have deployed into Syria's long war to support President Bashar Assad, as well as into Iraq in the wake of the 2003 U.S. invasion that toppled dictator Saddam Hussein, a longtime foe of Tehran.
Soleimani rose to prominence by advising forces fighting the Islamic State group in Iraq and in Syria on behalf of the embattled Assad.
U.S. officials say the Guard under Soleimani taught Iraqi militants how to manufacture and use especially deadly roadside bombs against U.S. troops after the invasion of Iraq. Iran has denied that. Soleimani himself remains popular among many Iranians, who see him as a hero fighting Iran's enemies abroad.