Updated

Threatening revenge and firing in the air, hundreds of gunmen on Saturday led a funeral procession for five Palestinian militants killed in an Israeli air strike.

The five, members of a group with close ties to the ruling Hamas movement, were killed late Friday in a neighborhood training ground for militants in Gaza City.

The airstrike further raised tensions between Israel and the Hamas-led Palestinian government, and sparked a new crisis for its leadership, which is under heavy international pressure to renounce violence.

Prime Minister Ismail Haniyeh of Hamas was to meet later Saturday with moderate Palestinian President Mahmoud Abbas to try to iron out growing differences of the division of power and relations with the international community, said government spokesman Ghazi Hamad.

Haniyeh has complained that Abbas has stripped the government of many of its powers. Abbas, in turn, wants Hamas to soften its hard line. The meeting comes at a time of growing a financial crisis resulting from bruising economic sanctions by the West.

Friday's attack hit a base used by the Popular Resistance Committees, an umbrella group responsible for numerous rocket attacks against Israel. During five years of fighting, the Israeli army has killed dozens of militants in airstrikes.

It was the first such attack approved by Israel's new defense minister, Amir Peretz, leader of the moderate Labor Party, and signaled the practice would continue under the new centrist government, sworn in earlier in the week. Peretz asked the army for assurances that no civilians would be harmed, Israeli security officials said.

The airstrike scattered body parts and left pools of blood in a field just meters (yards) away from the home of Moumtaz Dourghmush, the top militant commander in the resistance committees. Dourghmush was not at the scene, but a brother and three cousins were among the dead, hospital officials said.

Dourghmush is known to have close ties with Hamas' military wing and has received training and funding from the Islamic group in the past.

Israeli security officials say he was involved in an attack last month on the main Israel-Gaza commercial crossing. That attack, they say, was planned in coordination with Hamas.

Abu Mujahid, an official with the resistance committees, said at least three missiles landed in the field as members were training. "God willing, this is not going to stop our heroic battle against the Zionists, and the blood is the fuel of our resistance and our reprisal is coming soon," he said.

The army confirmed it had targeted the militants as they were training to carry out attacks. Later Friday and Saturday, the army fired artillery shells at suspected rocket-launching sites in northern Gaza.

Hundreds of gunmen led Saturday's funeral procession of thousands of mourners, firing in the air and chanting "revenge, revenge."

Since the Hamas government took office in late March, Israel has stepped up military activity in Gaza in response to repeated rocket fire. Earlier Friday, six rockets were fired toward Israel, the army said.

The rudimentary projectiles have not caused any serious casualties recently, but have been deadly in the past. While not directly involved in the rocket fire, Hamas has refused to condemn the attacks or take steps to stop them.

In addition to firing rockets, the Popular Resistance Committees has in the past blown up Israeli tanks and is widely believed to be behind the deadly bombing of a U.S. diplomatic convoy in October 2003.

Last month, Hamas appointed the head of the PRC, Jamal Abu Samhadana, to head a new security force. The appointment infuriated Israel and was vetoed by the moderate Abbas.

Hamas has vowed to push forward with its plan, announcing Saturday that the unit will begin operating on May 14. The controversial unit will back existing security forces in a crackdown on illegal construction along the Gaza coast, said Khaled Abu Hilal, a spokesman for the Interior Ministry.

The airstrike was the latest crisis for the beleaguered Hamas government.

The U.S. and European Union have cut off hundreds of millions of dollars in direct aid to the Palestinian Authority, demanding that Hamas end its calls for Israel's destruction. Hamas has refused to give in.

The cutoff in aid, along with Israel's suspension of tax and customs duties it collects for the Palestinians, has left the Palestinian government unable to pay 165,000 government employees for the past two months. The government is the largest employer in the Palestinian areas.

On Saturday, teachers in the West Bank city of Hebron went on strike at five schools, demanding their overdue paychecks in the first sign of unrest by public employees against the government. Hundreds of government workers — most of them Fatah supporters — also protested in the West Bank city of Nablus.

The demonstrations marked a turning point for Hamas. The Palestinian public has largely backed the government's contention that the crisis is the result of Western hostility to Hamas and heeded calls to remain patient.

Thousands of Palestinians demonstrated in support of Hamas on Friday throughout the West Bank and Gaza.

During the protests, Hamas leaders called on Arabs and Muslims around the world to boycott products from countries that are withholding aid. In Gaza City, protesters burned and trampled American, British and Israeli flags.