Palestinian leaders closed universities and schools in the Gaza Strip on Tuesday, a day after two Palestinians were killed and more than 210 hurt in the deadliest internal fighting in years, sparked by protests against the U.S. attacks on Afghanistan.

The clashes deepened the rift between the Palestinian Authority and Islamic militants at a time when Yasser Arafat is trying to persuade his rivals to honor a shaky truce with Israel.

Monday's events began when more than 1,000 students, many of them supporters of the militant Hamas group, marched in support of Afghanistan and Usama bin Laden.

After the march, dozens of demonstrators broke away and fought street battles with police in and around Gaza City's Islamic University. Protesters threw stones, while police fired tear gas and beat protesters with clubs. There were also exchanges of gunfire.

Doctors said 142 Palestinian security personnel and 72 civilians were injured in that confrontation and in subsequent clashes throughout the night. Several victims were hit by gunfire.

Gaza City was quiet Tuesday morning, with roads around some security bases closed to civilian traffic. Gaza City's two universities, the Islamic University and Al Azhar University, were closed until the end of the week. Schools were shut for a day.

The Palestinian Authority convened heads of the main activist groups on Monday night in an attempt to halt further street battles. In a joint statement after the meeting, the factions expressed "deep pain over the grave incident."

The statement condemned the use of live ammunition during Monday's clashes. Police said masked men fired at them from within the campus. Human rights groups, including London-based Amnesty International, said security forces used excessive force.

Hamas spokesman Ismail Abu Shanab denied shots were fired by the protesters and said only the police had weapons. "We are looking to find out who is responsible and who are those people who fired against the unarmed students," he said.

The Palestinian Authority said a commission of inquiry would be formed. It said Monday's events harmed the Palestinians' image abroad and threatened national unity.

The Palestinian Authority has tried to distance itself from bin Laden, and has also tried to persuade Hamas to honor a Sept. 26 truce with Israel.

However, Hamas has not observed the truce and is opposed to the U.S. bombing campaign. Some Hamas supporters carried pictures of bin Laden at Monday's protest.

Bin Laden has issued a call for Muslims to support the Palestinian cause, saying that "neither America nor the people who live in it will dream of security before we live it in Palestine."

In the West Bank town of Nablus, Hamas planned to stage a rally Tuesday to protest the police clampdown in Gaza City, but the event was canceled, Hamas officials said.

During Monday's rally, security forces chased away journalists and told them not to report on the demonstration, part of an ongoing effort to prevent reporting about rallies with expressions of support for bin Laden.