GAZA CITY, Gaza Strip — Israel's army dropped leaflets Thursday warning residents of attacks on homes believed to be hiding militant weapons as air and ground forces raided a Gaza refugee camp for a second day, killing three Palestinians.

The army has adopted a new policy of attacking homes in civilian areas where weapons, such as the homemade rockets routinely fired into Israel, are secretly stored, military officials told The Associated Press, speaking on condition of anonymity because they were not authorized to give information to the media.

The Arabic-language leaflets dropped over Gaza City warned that "anyone who has, or is keeping an arsenal, ammunitions or weapons in their house must destroy it or they will face dangerous consequences."

The Israeli offensive began after Hamas-linked militants captured an Israeli soldier in a June 25 cross-border raid.

More than 100 Palestinians have been killed in the violence, the U.N. reported. Many of the victims were gunmen, but at least 16 were minors. Israeli forces have mostly attacked government compounds and open areas militants use to fire rockets toward Israel.

The offensive has continued even as Israel waged a new campaign in Lebanon against Hezbollah, which began July 12 after guerrillas crossed the border and captured two soldiers.

On Thursday, Israeli aircraft carried out a series of strikes against Palestinian militants in the Mughazi refugee camp in central Gaza, the army said. Two militants were killed and at least 15 people, many of them civilians, were wounded, Palestinian medical officials said.

Earlier Thursday, a Palestinian teenager was killed in Mughazi as militants and troops exchanged fire, doctors said. A 10-year-old Palestinian girl also died of wounds suffered in an airstrike a day earlier, doctors said. Nine people, eight of them militants, were killed in the area in Wednesday's fighting.

Israeli forces also fought with Palestinians in the West Bank city of Nablus, where a standoff between troops and militants pressed into a second day. Troops and tanks surrounded a security compound where the militants were holed up.

Tanks fired five shells at the buildings to try to force the militants inside to surrender. Israeli troops fired steel-coated rubber bullets at protesting Palestinians, wounding five, one seriously, Palestinian medics said.

About 4,000 Palestinians demonstrated in Nablus in support of Hezbollah, calling on the militia's leader, Hassan Nasrallah, to attack Israel with rockets.

"Nasrallah, our dearest, strike, strike Tel Aviv," the Palestinians shouted.