Palestinian Authority Chairman Mahmoud Abbas on Wednesday lashed out at Palestinian militant factions, particularly the Islamic Jihad and Hamas, saying they had no right to selectively violate the ceasefire with Israel.

In a speech to the PA cabinet, Abbas sharply criticized Palestinian militant factions for provoking Israeli attacks by violating the ceasefire.

"No one has the right to respond here and there, unilaterally," he told parliament.

"The occupation is criminal but we cannot give Israel excuses to attack us," he said.

In particular, Abbas rebuked Hamas for blaming Israel for the deaths of 18 Palestinians in a blast caused by Hamas ammunition during a rally by the group in the Jabalya refugee camp in September.

"I am not here to defend the Israelis," Abbas said, "but with regard to the incident in the Jabalya refugee camp, Israel was not involved. We are talking about an internal [Hamas] mistake.

Following Abbas' speech to the cabinet, Palestinians fired a mortar shell Wednesday afternoon that hit Moshav Netiv Ha'asara, located just north of the Gaza Strip. The shell landed in a soccer field. There were no casualties.

Later on Wednesday evenin, Palestinians fired a second mortar shell that hit near near the border fence between southern Gaza and Israel. There were no casualties.

Abbas also said Wednesday that only an "act of God" would delay Palestinian parliament elections set for January 25, dismissing speculation that he would postpone the vote because of disarray in his Fatah movement, the rise of Hamas and growing chaos in the West Bank and Gaza Strip.

Abbas spoke to parliament after the Islamic militant Hamas, his biggest political rival, suggested it would not support a truce with Israel beyond 2005 if the election is postponed. The truce deal, struck in February with several Palestinian militant groups, includes a pledge by Abbas to hold such an election.

In opening the parliament session, Speaker Rauhi Fattouh suggested that it would be difficult to hold the parliament election if chaos is not brought under control.

However, Abbas told legislators he would not seek a delay. "The election will be held on Januaru 25, and nothing will delay it, except for an act of God," Abbas said.

Defying parliament, Abbas also said he would not reshuffle his Cabinet before the election.

Earlier this month, legislators had demanded that Abbas appoint a new government immediately to wage a more effective battle against lawlessness. It was not clear whether legislators would now revive an earlier threat to bring down the government in a no-confidence vote.

IAF missile hits northern Gaza Strip in wake of rocket fire Abbas' speech to parliament came after an Israel Air Force aircraft fired at least one missile at an open field in the northern Gaza Strip early Wednesday, about two hours after Palestinian militants launched a homemade rocket into the Negev town of Sderot.

Ground forces also aimed artillery fire at the area, the army said, and several sonic booms caused by Israeli warplanes were heard in Gaza during the night.

The air strikes, which landed in the Beit Hanun area, caused no injuries or damage, Israel Radio reported. A Palestinian official said Israel had warned that Palestinian civilians should stay away from the area.

An Israel Defense Forces source said the strikes were "warning shots into an open area from where Qassam rockets were launched," in an effort to prevent further attacks.

There were no reports of damage or injuries from the air strike or the rocket attack on Sderot, for which the Al-Aqsa Martyrs' Brigades, an armed wing of Palestinian Authority Chairman Mahmoud Abbas's ruling Fatah movement, claimed responsibility. Sderot is a frequent target of Palestinian militants due to its proximity to the Gaza Strip.

The recent escalation of violence has been exacerbated by Monday's killing of Luay Sa'adi, one of the Islamic Jihad's top West Bank leaders, by IDF troops in a shootout. The militant group issued a statement promising to avenge the death of Sa'adi, who was buried Tuesday morning in Tul Karm. His funeral was attended by tens of thousands of Palestinian mourners.

Hours after the shootout, Islamic Jihad militants launched five Qassam rockets into Israel from the Gaza Strip, to which Israel responded with a series of air strikes Tuesday at targets in Gaza.

IDF troops arrested three wanted Tanzim and Islamic Jihad militants in the West Bank before dawn Wednesday, Army Radio reported.

The Palestinian Authority said Tuesday it had deployed troops to areas in the northern Gaza to stop rocket fire into Israel.