At least 10 pro-Palestinian activists were killed during an Israel Defense Forces raid on the ships and dozens were injured. Four soldiers were hurt, one sustaining serious wounds.
Chief Palestinian negotiator Saeb Erekat told the al-Jazeera network that Arab League Secretary-General Amr Moussa accepted Abbas' request to hold an urgent Arab League meeting following the events.
Haniyeh called an emergency cabinet meeting for Monday morning. Hamas spokesman Sami Abu Zuhri described the Israeli operation as a crime reflecting the Israeli character. He called on Arab and Muslims worldwide to revolt against Israel's embassies in order to pressure the Israel Defense Forces to release the activists and help them reach Gaza.
Senior Islamic Jihad member Muhammad al-Hindi said that the Palestinian sea, which was a cemetery for all invaders, would also be a cemetery for the Israeli enemy.
Jamal al-Hudri, head of the Popular Committee to Fight the Blockade in the Strip, slammed the Israeli operation and called for quick international action by the 40 countries from where the international activists originated in order to stop "the Israeli massacre".
Ahmed Yusef, a representative of the Palestinian foreign ministry in the Strip, described the Israeli operation as a great crime and pirate hooliganism. He called on the Turkish government to sever its ties with Israel.
Palestinian Parliament Member Mustafa Barghouti condemned the Israeli operation and referred to it as a massacre and act of piracy against international activists and lawmakers. He noted that the operation was part of Israel's collective punishment against the Palestinian people.
Meanwhile, Hamas' security forces have reinforced their deployment and patrols near the border fence with Israel in order to prevent the firing of rockets at southern Israel in response to the events.
Sources in the Strip estimated that the Palestinian organizations would fire rockets at Israel in the coming hours, and Hamas hopes the firing will not lead to a wide-scale Israeli operation in the Gaza Strip.
Hamas' security forces are taking a series of steps in order to prevent an escalation in the Strip, despite the organization's rage over the Israeli operation.
'Bibi belongs in garbage can of history'
In Israel, Hadash Chairman Mohammad Barakeh "congratulated" the prime minister and defense minister for "the shining victory of their pirate army on the freedom civilian sail.
"The crimes of the pirate government in killing some of the sail's participants put the government beyond international and human law. Tyrants like Prime Minister Benjamin Netanyahu and Defense Minister Ehud Barak will find themselves in the suitable place in the garbage can of history," he said.
Balad Chairman Jamal Zahalkja referred to the takeover as "a massacre". He said the Arabs in Israel were infuriated by the events. "This is an operation which was planned for weeks. They issued an order to prevent the ships' entry at any cost. This morning that cost was revealed. In October 2000 they also opened the Wadi Ara road at any cost, and 13 of our sons were killed."
Zahalka added that he turned to official elements in the government and Knesset to inquire about the condition of members of the Higher Arab Monitoring Committee's delegation who joined the sail, but did not receive any details.
Knesset Member Ahmad Tibi (United Arab List-Ta'al) said, "This is an abominable crime and a mass slaughter of the Israeli occupation army against an unarmed sail. The world must respond to this murderous rampage."
Sharon Roffe-Ofir contributed to this report