GAZA CITY, Gaza Strip ? Israel tried to kill the mastermind of the Hamas bombing campaign Thursday, firing two missiles from a helicopter into a car in crowded Gaza City and killing two bodyguards. Thirty-five bystanders were wounded, but the fate of the Palestinian militant remained uncertain.

A senior Palestinian security official said Israel’s target, 37-year-old Mohammed Deif, escaped with moderate injuries. Israeli police sources said the Israeli military told them Deif atop Israel’s wanted list for years was killed. The military had no comment.

Hamas official Abdel Aziz Rantisi said Deif was not in the car. But he said the group would avenge the attack nevertheless. “We will hit Tel Aviv. We will hit everywhere.”

Hamas and the Palestinian Authority are rivals, possibly explaining the different versions of Deif’s fate.

In a predawn raid today, Israeli soldiers carrying out a house search shot and killed an armed 21-year-old Hamas militant in the West Bank city of Hebron, Palestinian witnesses and hospital officials said. The army declined immediate comment.

In other violence, four Palestinians including two gunmen, a civilian and a baby and one Israeli were reported killed.

Israel maintained its stranglehold on Palestinian leader Yasser Arafat’s headquarters in the West Bank town of Ramallah in defiance of Tuesday’s U.N. Security Council resolution to end the siege.

Hamas sources identified the two men killed by the missiles as members of Hamas: Abdel Rahim Hamdan, 27, and Issa Abu Ajra, 29. Rantisi said they were Deif’s bodyguards.

More than a dozen children also were wounded in the attack.