Palestinian security sources said about 25 tanks and Jeeps entered the camp and troops surrounded a number of houses, using explosives to blow the doors in.

There were no reports of any arrests or injuries.

The Israeli army arrested six Palestinians overnight in the West Bank on suspicion of being involved in anti-Israeli attacks, sources said on Monday.

Most of those rounded up in the town of Qalqilya are believed to be members of the Popular Front for the Liberation of Palestine (PFLP).

They included a senior member of the PFLP's armed branch who was captured by special forces dressed in civilian clothes, a Palestinian source said.

The PFLP claimed responsibility for an attack on 25 December at a bus stop on the outskirts of Tel Aviv which killed four Israelis as well as the bomber.