The militant group Hamas, which rules Gaza, said it was behind the operation and dubbed it “Al-Aqsa Flood.”

The Hamas incursion, stunning in its boldness and complexity, marked a major escalation of its conflict with the Israeli government.

“Enough is enough,” the elusive leader of the group’s military wing, Mohammed Deif, said in a recorded message that called on Palestinians to join the fight.

“This is the day of the greatest battle to end the last occupation on earth,” he said, adding that 5,000 rockets had been launched.

The militant group said it had taken a large number of hostages, including senior Israeli officers.

NBC News was not able to independently verify these claims.

Western leaders lamented the outbreak of violence.

President Joe Biden said the U.S. “unequivocally condemns this appalling assault against Israel by Hamas terrorists from Gaza.” He said he told Netanyahu in a call that “we stand ready to offer all appropriate means of support to the Government and people of Israel.”

“Terrorism is never justified. Israel has a right to defend itself and its people. The United States warns against any other party hostile to Israel seeking advantage in this situation,” Biden said in a statement.

European heads of state — including German Chancellor OIaf Scholz and French President Emmanuel Macron — excoriated Hamas and expressed solidarity with Israel.