Enlarge By Uriel Sinai, Getty Images Israelis rally in Tel Aviv to support their country following a military encounter at sea that left nine dead. JERUSALEM  Israel defended itself Monday against accusations it overreacted to a flotilla of pro-Palestinian activists it said provoked a battle with Israeli commandos that left nine activists dead and several soldiers severely injured. "The armada of hate and violence in support of the Hamas terror organization was a premeditated, outrageous provocation," Deputy Foreign Minister Danny Ayalon said. Thousands of people in Turkey protested the deaths of the activists, many of whom were Turks. Turkey's government called the incident "state-sponsored terrorism." The United Nations Security Council, which held an emergency meeting Monday, called for an impartial investigation of the raid. U.S. Deputy Ambassador Alejandro Wolff urged Israel "to investigate the incident fully." President Obama voiced "deep regret" over what occurred. Six ships carrying humanitarian aid left Cyprus to breach a blockade of Gaza set up by Israel and Egypt to keep arms from Hamas. Designated a terror group by the United States and other countries, Hamas took control of Gaza in 2007 and has rained more than 6,500 rockets onto Israeli towns. Israeli Defense Minister Ehud Barak said the ships were contacted and told they could offload supplies at an Israeli port for delivery to Gaza, but they refused. According to Barak, Israeli commandos boarded five of the ships and forced them to dock, but dozens of activists on the Turkish-flagged Mavi Marmara used guns, knives and bats to attack commandos. The commandos were armed with paintball rifles but got the OK to use their pistols when one commando was thrown 30 feet onto a lower deck and another soldier lost his handgun to an attacker. Israel Prime Minister Benjamin Netanyahu, who canceled a planned meeting with Obama, said he regretted the loss of life but said the soldiers "had to defend themselves." Palestinian President Mahmoud Abbas condemned the "massacre." Jews and Arabs viewed the killings differently. "It hurts to think that the food and medicine didn't make it to the people of Gaza," said Mazen Sublaban, an Arab music teacher in East Jerusalem. "Hamas is defying international law, but no one cares about that," Ofer Kadesh said. After nightfall, a rocket was fired into Israel. Hamas-linked militants said it was in response to the raid. No one was hurt. Contributing: The Associated Press Guidelines: You share in the USA TODAY community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language decent. Use the "Report Abuse" button to make a difference. You share in the USA TODAY community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language decent. Use the "Report Abuse" button to make a difference. Read more