Israeli troops and Palestinian gunmen traded heavy fire during a standoff at a fugitives' hideout Saturday, and doctors said a 16-year-old Palestinian was killed.

Twenty Palestinians were wounded in the clashes in the West Bank city of Nablus, the doctors said.

The standoff began early Saturday when troops surrounded a four-story apartment building where the army said two Palestinian fugitives were hiding. Troops called on the fugitives to surrender, but by mid-afternoon, they were still inside the building.

The army brought in bulldozers who started chipping away at the walls of the building and destroyed a water tank. At one point, the building came under heavy automatic fire by the army.

The troops also fired at a neighboring house, where gunmen were seen shooting at the force.

Bulldozers and army vehicles driving through the neighborhood were showered with stones.

The residents of the building were ordered to leave and some where questioned, the witnesses said. Troops also searched neighboring buildings, witnesses said, and soldiers carrying guns were seen moving between houses.The neighborhood appeared deserted and heavy gunshots were exchanged.

The army said Palestinians fired at the troops and in two cases also hurled explosive devices. Troops fired back, in one incident wounding a Palestinian in the lower part of his body, the army said.

A 16-year-old Palestinian arrived dead at a local hospital with a shot to the back, doctors said. Twenty more Palestinians were wounded, half of them by live fire and the others by rubber-coated steel bullets, doctors said. One of the wounded was in critical condition with an abdominal wound, doctors said.

The wanted militants belong to the Aqsa Martyrs Brigades, an offshoot of Fatah. They are believed to be explosive experts.