Israel on Tuesday tried but failed to assassinate members of the militant Islamic group Hamas in Gaza City. At least 11 Palestinians were reported wounded in the operation.

An Israeli helicopter fired two missiles at a car carrying militants from the Hamas group late Tuesday in Gaza, wounding two of the passengers and several onlookers.

A crowd of hundreds of angry Palestinians gathered round the damaged vehicle, which had been heading towards the Sheikh Radwan neighborhood when it came under attack.

One of the wounded is reported to be Jamal al-Jarah, a senior member of Hamas' military wing, a group which has carried out frequent suicide bombings.

The Israeli army issued a statement confirming that it had targeted senior Hamas members who it says were "actively engaged in planning terror attacks. A spokesman for the Israeli foreign ministry said the operation was justified because Israel has the right to take whatever actions are necessary to defend itself against terrorism. He also noted that Hamas has dedicated itself to Israel's destruction.

In response to the Israeli operation, Hamas immediately vowed to continue what it calls its campaign of resistance against Israel. The spiritual leader and founder of Hamas, Sheikh Ahmed Yassin, says Israel will pay "a heavy price" for the Gaza military strike.

During more than three years of fighting, Israel has carried out many similar air-strikes against Palestinian militants.

Israeli helicopters struck in the Gaza Strip last Thursday, killing three members of the Islamic Jihad, another group that carries out frequent suicide bombings. Two civilians were also killed in the attack.

Earlier on Tuesday, Israeli forces swept back into the West Bank city of Nablus, exchanging gunfire with Palestinian militants and imposing a curfew in the center of the city.

Israeli soldiers are continuing searches for wanted Palestinian militants believed to be hiding out in Nablus, an area that Israel describes as a "hotbed of terrorism."