11.   Palestinian gunmen fired at the troops, setting off a heavy exchange of fire.

12.   Palestinian security officials said Israeli forces entered Yatta town, just south of Hebron, before dawn Saturday, withdrawing about four hours later after heavy exchanges of fire.

13.   Palestinians fired an anti-tank grenade at the district liaison office in southern Gaza on Thursday, the military said, during a heavy exchange of gunfire nearby.

14.   A heavy exchange of fire accompanied the Israeli operation in the Rafah refugee camp in the early hours of Tuesday.

15.   A heavy exchange of fire accompanied the Israeli operation in the Rafah refugee camp.

16.   A heavy exchange of fire lasted until late Sunday, the sources said.

17.   A heavy exchange of gunfire erupted Monday night south of Jerusalem.

18.   A spokesman for the rescue services said heavy exchanges of fire were preventing ambulances from entering the area.

19.   A twelfth Palestinian was shot dead amid heavy exchanges of fire between Israeli troops near the southern edge of Jerusalem and Palestinian gunmen in adjacent towns and villages.

20.   A thirteenth Palestinian was shot dead amid heavy exchanges of fire between Israeli troops near the southern edge of Jerusalem and Palestinian gunmen in adjacent towns and villages.