An Israeli helicopter fired two missiles into Gaza City early Sunday, killing three members of Hamas and wounding seven bystanders, Palestinian witnesses said.

Hamas, or the Islamic Resistance Movement, identified one of the dead men as Wael Nassar, a high-profile leader of the group's military wing, known as the Izzedine al-Qassam Brigades, who had been wanted by Israel for years.

Hamas said Nassar was the architect of a May 11 ambush in which six Israeli soldiers were blown up when their troop carrier rolled over a mine during a raid in the Gaza City neighborhood of Zeitoun.

Palestinian medics said three of the seven civilian wounded were in critical condition. A woman and two children were among the casualties, they said.

The Israeli army had no immediate comment.

The Associated Press reported that a Palestinian gunman killed an Israeli officer Saturday morning after opening fire on Israeli troops conducting a raid in a West Bank refugee camp known as a hotbed of militants.

Israeli troops have been operating in the Balata camp, just outside the northern West Bank city of Nablus, in recent days in an effort to root out Palestinian militants.

The company commander, Capt. Shachar Ben Ishay, 25, was shot once in the side, the army said. He was treated at the scene but died from his wounds as he was being transported to the hospital, the military said.