AL QUDS: Having bathed in the dreamy tranquillity of Sharm El-Sheikh and imbibed the heady atmosphere of their ceasefire summit at the Egyptian Red Sea resort , both Israeli Prime Minister Ariel Sharon and Palestinian leader Mahmoud Abbas returned to considerably less attractive political landscapes at home.

Abbas was greeted less than 48 hours after his return with a barrage of mortars fired by Hamas militants at Jewish settlements in Gaza, in brazen defiance of his commitment to a truce. Sharon returned to growing calls, now led by his foreign minister, for a referendum on his plan to withdraw from Gaza - a move he virulently opposes.

No one was injured during the salvo on Thursday morning in which Hamas militants fired close to 50 rockets at settlements in southern Gaza, in what they said was retaliation for the death of a Palestinian man shot dead by Israeli troops on Wednesday near a settlement. The same day as the rocket barrage, a group of Palestinian militants blasted their way into the main prison in Gaza, hauled out three inmates and shot them dead in what appeared to be a settling of scores in a clan feud.

If the Hamas rocket attacks were a blatant violation of Abbas' commitment to end all violence, the attack on the prison was a direct blow to his pledge to establish law and order in the West Bank and Gaza. He moved swiftly, however, sacking three senior Palestinian Authority security chiefs.

The move was meant to broadcast an unequivocal message - that Abbas would not tolerate violence by militants, whether it be against Israel or among Palestinians themselves. Abbas was also signalling his readiness to shuffle the top echelons of the Palestinian security forces and appoint men loyal to him. The three men who were fired were all Yasser Arafat appointees. Abbas also convened an emergency session of the central committee of the ruling Fatah party to discuss the shelling. The committee released a harsh statement saying the Palestinian security forces would "deal with the severe security violations, the attempts to undermine the Palestinian Authority's deterrent capabilities, and the attempts to undermine its international commitments."

The Palestinian leader is meeting Hamas leaders in Gaza on Saturday to urge them to cease the mortar fire and to warn them he will not countenance any violations of the truce he agreed with Sharon at the Sharm summit. Until now, Abbas has rejected Israeli and US demands that he use force to crush armed groups. Warning of the danger of civil strife, he has said he will employ dialogue in trying to persuade militants to hold their fire. But if groups like Hamas continue to defy his call for "one law, one gun," he may have to reconsider his reluctance to use force. Some of his security chiefs have apparently been urging him to do so, especially in Gaza where Hamas has its stronghold. Israel said it would not respond with military action to the mortar strikes because it wanted to give Abbas more time to act. But some ministers warned that the government's patience was limited. "If the Palestinians don't know how to deal with it, we will deal with it," said Israeli Defence Minister Shaul Mofaz, in reference to the mortar attacks.

For now, Sharon is probably thinking more about setting Mofaz on some members of his own party. Peeved at not having been invited to tag along with Sharon to Sharm and believing he could make some political profit inside the ruling Likud party, Foreign Minister Silvan Shalom announced just hours after the summit finished that he would lead the campaign for a referendum on Sharon's plan to evacuate all 21 settlements in Gaza by the end of the summer.

Turning up the heat further on Sharon, the speaker of the parliament, Reuven Rivlin, once a loyal ally of Sharon, also joined the call for a referendum. Sharon reacted swiftly: "There will be no referendum", was his emphatic response to reporters' questions.

The most vociferous supporters of a referendum are almost all on the right of the political spectrum and oppose a withdrawal from Gaza.-Dawn/The InterPress News Service.