Updated

Three Palestinian gunmen were killed and three others wounded in an Israeli air strike in the Khan Younis (search) refugee camp in southern Gaza after nightfall Thursday, witnesses and Palestinian security officials said.

This came during an expanding Israeli operation in the camp, they said. Israel now has 30 tanks and armored vehicles in the camp, and just before the air strike, the Israelis blew up a two-story building, they said. The Israelis sent 10 tanks into the camp just after midnight Thursday to begin its third raid there in two weeks.

The Israeli military said the air force spotted four armed men moving in the camp and fired at them. Israeli forces have been trying to stop militants from firing mortars and rockets at nearby Jewish settlements (search) and army bases.

Five Palestinians, including three Hamas (search) militants and two civilians, were killed in earlier clashes in the camp on Thursday.