RAMALLAH, West Bank ? Palestinian leader Yasser Arafat has signed a package of laws granting basic rights to his people and regulating his government, officials said Thursday, just before world diplomats began arriving to press him for reforms.

In the latest of almost nightly incursions into Palestinian towns, Israeli troops early today entered Nablus in about 40 tanks and armored personnel carriers, Palestinians said. They were heading for two refugee camps and surrounded the Balata camp, headquarters of the Al Aqsa Martyrs Brigade militia, linked to Arafat’s Fatah movement.

Israeli Army soldiers march out of the Shuafat refugee camp in East Jerusalem after conducting a security sweep in the area. Early today, Israeli tanks moved into the West Bank town of Nablus in a security move.

Israeli military sources, speaking on condition of anonymity, confirmed that the operation was under way. Residents said Palestinians had set off two mines under Israeli tanks, and the tanks had fired five shells, knocking out electricity in the eastern part of Nablus.

On Thursday, Palestinian officials confirmed that two days earlier Arafat had signed the Basic Law, which had been sitting on his desk for five years. It is a kind of framework for a constitution.

The signing came ahead of a parade of diplomats visiting Ramallah.

The sudden stream of high-level diplomats to the region indicated renewed world efforts to put an end to the conflict before it threatens other world efforts, like the struggle against international terrorism.

Israeli Prime Minister Ariel Sharon has said that peace negotiations cannot resume until the Palestinian regime is reformed. The Israeli view is that Arafat himself must be kicked upstairs to a ceremonial position, while someone else runs affairs of state. Palestinians bristle at the Israeli demands.