IDF troops backed by IAF aircraft and tanks clashed with Palestinian gunmen in the southern Gaza Strip on Sunday, and health officials said nine gunmen were wounded. The army said the operation Sunday targeted terrorists who regularly fire rockets and mortars at the western Negev. It confirmed air-strikes but had no further details. Hamas said the battles began around 1 a.m. after undercover soldiers infiltrated houses east of the town of Rafah. Tanks and bulldozers moved across the border into Gaza to back the troops, and IAF aircraft struck twice, Hamas said. The bulldozers were razing farmlands in an effort to deny rocket squads cover, and the army was carrying out arrest sweeps of men under 45, Hamas and local residents said. According to Hamas, at least 25 men were arrested.