Jewish advocacy groups were quick to speak out Monday as the White House said it "regrets" and is looking further into an Israeli military raid on an aid flotilla to the blockaded Gaza Strip.

The American Jewish Committee put out a statement Monday condemning the "pro-Hamas 'Free Gaza' movement and its supporters for deliberately provoking a violent confrontation with the Israeli Navy." At least nine activists were killed in the raid, though some Arab news outlets were reporting twice that number.

"This tragedy on the high seas could have been avoided, and we regret the loss of life,” said AJC Executive Director David Harris. “The fact that the flotilla refused to cooperate with Israel’s repeated entreaties to unload their humanitarian cargo in Ashdod for delivery to Gaza proves that violent clashes are exactly what the international supporters of Hamas must have been seeking."

The Israel Ministry of Foreign Affairs said Monday that the Israel Defense Forces attempted to stop the six ships in order to try to get the flotilla to transport the aid materials through proper security inspections.

"During the boarding of the Marmara ship, the demonstrators onboard attacked the IDF naval personnel with live fire and light weaponry including knives and clubs," the Foreign Ministry said. "Additionally two of the weapons used were grabbed from an IDF soldier. The demonstrators had clearly prepared their weapons in advance for this specific purpose." 

Israel posted YouTube videos showing the melee along with its statement.

"The ironically-named 'Free Gaza' movement, which exists to bolster the despotic Hamas regime and its Muslim Brotherhood support base in Turkey and elsewhere, sailed this flotilla not to deliver humanitarian aid — which Israel offered to deliver by land after a security check — but to add an international dimension to the relentless campaign of Hamas against Israel's very existence," said Harris.

J Street put out a statement Monday stressing that the incident showed stronger American leadership is needed to end the conflict in the Middle East.

"Today is one more nail in the coffin for hopes of ending the Israeli-Palestinian conflict peacefully and diplomatically and for preserving Israel’s Jewish and democratic character," spokeswoman Jessica Rosenblum said. "We urge President Obama and other international and regional leaders to take today’s terrible news as an opportunity to engage even more forcefully in immediate efforts to end the Israeli-Palestinian conflict."

J Street also called for a "credible, independent commission appointed by the Israeli government" to investigate the incident and fully disclose its findings.

"This shocking outcome of an effort to bring humanitarian relief to the people of Gaza is in part a consequence of the ongoing, counterproductive Israeli blockade of Gaza," Rosenblum said.

Israel advocacy group StandWithUs put out a statement noting that Israel had previously intercepted boats carrying weapons to Gaza.

"It should not come as a surprise that any country’s navy would find it necessary to board and search a vessel attempting illegally to enter their sovereign shores," the Monday statement read. "What is surprising is that the Israeli security personnel were brutally attacked with knives, lead pipes, and other weapons when they carried out predictable and routine security procedures."

The group said it regretted the loss of life, but said the flotilla "provoked a confrontation" with Israeli forces.

"The flotilla organizers could have sincerely sought peace by urging Hamas to recognize Israel as the Jewish State, accept past Palestinian-Israeli agreements, and reject terrorism and violence," StandWithUs said. "Instead, the flotilla activists endorse Hamas’ current extremism and belligerence."

This post was updated at 1 p.m.