The Palestinian militant group Islamic Jihad said on Tuesday any possible truce with Israel would not restrict its right to respond to strikes by the Jewish state in the West Bank.

Abu Emad al-Rifaie, a senior member of Islamic Jihad, said the group told Egyptian mediators that it approved -- with qualifications -- a Hamas proposal for a truce with Israel that starts in the Gaza Strip.

"This approval is under the condition that in the event of any Israeli aggression against our mujahideen (fighters) or people in the West Bank ... we reserve our right to respond to such massacres," he told Reuters in Cairo after talks with Egyptian intelligence chief Omar Suleiman.

The Islamist movement Hamas has said extending the ceasefire to Palestinians in the Israeli-occupied West Bank was "an option".

Egypt invited 12 Palestinian groups for talks to form a consensus on Hamas' six-month ceasefire proposal last week between Palestinians and Israel. Hamas, which controls Gaza, said the proposal would also include an end to the Israeli-led blockade on the strip.

Israel, which wants Palestinians to stop firing cross-border rockets, has dismissed the offer as a Hamas ploy to gain time to prepare for more fighting.

Abou Adnan al-Baba, member of the central command of the Popular Resistance Committees (PRC), said his group has agreed to drop the condition that the truce start in Gaza and the West Bank simultaneously.

Baba said the PRC, a coalition of factions that includes armed wings firing rockets against Israel, would keep its "eyes open and decide how to deal with the situation in time" if Israel launched military operations in the West Bank.

Ramzi Rabah, a senior member of the Democratic Front for the Liberation of Palestine, said his group told Suleiman the truce should start in all Palestinian territories. "Egypt said it understands our position," he said.

A truce between Israel and the Palestinians in Gaza would lift some pressure off Egypt, a key regional mediator, which does not want to be viewed as aiding the blockade on Gaza or see Palestinian militants storm its border with the coastal strip as Hamas gunmen did earlier this year, allowing hundreds of thousands of Gazans to cross into Sinai.

Failure of Palestinians to reach common ground or Israeli rejection of the truce would complicate Egyptian efforts to end violence in the Gaza Strip.

The talks in Cairo, which will continue on Wednesday, were overshadowed by the killing of six Palestinians, including four children and their mother, as they were having breakfast on Monday in the Gaza town of Beit Hanoun.

Israel said the deaths were tragic and occurred when an aircraft fired at two Palestinian militants carrying munitions, which exploded and destroyed the home of the family.

Nasser Ezzat, a senior member of the Popular Front for the Liberation of Palestine, said his group doubted any truce with Israel was viable but would not breach the Palestinian consensus.

"The Popular Front in principle does not see the truce issue as a correct stance as long as there was still occupation," he told Reuters.

Israel pulled troops and settlers out of the Gaza Strip in 2005 but still controls its borders and has tightened its restrictions since Hamas seized control there last year.