Palestinian Hamas spiritual leader Sheik Ahmed Yassin was killed early Monday in an Israeli missile attack, Hamas officials confirmed.

Witnesses said Israeli Apache helicopters fired three missiles at Yassin and his two bodyguards as they left a mosque. The men were killed instantly.

Four people died and 12 were wounded in the attack, witnesses said. Ambulances and fire trucks raced to the scene.

Thousands took to the streets after news of Yassin’s assassination spread, shouting for revenge, while hundreds of militants all over the Gaza Strip fired weapons into the air.

Hamas’ military wing, the Ezzedin al-Qassam Brigade, vowed in a statement to avenge the killing of its spiritual leader with immediate reprisals.

“We, the Ezzedin al-Qassam leaders, have decided to make immediate reprisals, like an earthquake that will hit everywhere to destroy the Zionist presence,” said the statement, adding that the response would be “unexpected.”

“Words cannot describe the anger and hate inside our hearts,” said Hamas official Ismail Haniyeh, a close associate of Yassin.

The Hamas leaders said, “Sharon has opened the gates of hell. And nothing will stop us from cutting off his head.”

Israel’s deputy defense minister Zeev Boim told public radio that “Sheikh Yassin deserved to die for all the terrorist attacks committed by Hamas.”

Boim made the remark in the first reaction by the Israeli government to the killing of Yassin, who founded Hamas in 1987 and was held in Israeli prisons for several years before being released in 1994.

Following the assassination of the Hamas chief, Israel closed the Erez crossing between the Gaza Strip and Israel.

(Xinhua News Agency March 22, 2004)