Without endorsing the ceasefire declared at the landmark Middle East summit, Palestinian resistance groups have said they will hold off on attacking Israel for now. Two major groups, Hamas and Islamic Jihad, reacted on Wednesday to pledges by Palestinian President Mahmud Abbas and Israeli Prime Minister Ariel Sharon to end violence at the Sharm al-Shaikh summit. Both resistance groups said they were not bound by the truce. But the two did not seem ready to alienate Abbas when they reiterated their readiness to observe a one-month "period of calm" as agreed with the Palestinian leader in late January. "Hamas endorsed (the need for) calm and will respect that to allow Abbas to ease into his job and exert pressure on the enemy," a spokesman said.