More than 50 Palestinians took out a full-page newspaper ad Wednesday condemning homicide bombings, a move that sparked debate at a time when most Palestinians support the attacks as an effective way to hit Israel.

The ad in Al Quds, a leading Palestinian daily, appeared Wednesday morning — a day after a homicide bombing killed 19 people on a Jerusalem bus, and hours before another homicide attack killed seven more people at a bus stop in the evening.

In the ad, the Palestinians urged the militant groups behind deadly assaults on Israeli civilians to "stop sending our young people to carry out such attacks."

"We see no results in such attacks, but a deepening of the hatred between both peoples and a deepening of the gap between us," the ad said.

The signatories included Hanan Ashrawi, a leading Palestinian spokeswoman and a legislator, and the Palestinians' senior Jerusalem official, Sari Nusseibeh, along with other prominent figures regarded as moderates. The ad urged other Palestinians to join them in their opposition to the bombings.

Among the others who signed the statement were noted Gaza human rights activist and psychiatrist Iyad Serraj, newspaper editor Hana Siniora, prominent economist Mohammed Ishtaya, Yasser Arafat's security adviser Mamdouh Nofal and Abdel Khader Husseini, son of the late Faisal Husseini, who was Nusseibeh's predecessor as top Palestinian official in Jerusalem.

"We felt we had to chart a course, not just break the silence," Ashrawi said. "We wanted to create a momentum to get people to think with their minds and to reason, instead of always reacting emotionally and out of revenge and pain and trauma."

With the latest attacks, Palestinians have carried out 71 homicide bombings in the past 21 months of Mideast fighting, killing about 250 people on the Israeli side.

The attacks outrage Israelis, and the government has responded with military strikes and incursions into Palestinian territory, aimed at suspected militants as well as buildings belonging to the Palestinian Authority government and security forces. Israeli Prime Minister Ariel Sharon says Palestinian leader Yasser Arafat is ultimately responsible for failing to stop the attacks.

Palestinians have held virtually no public debate on the issue. Polls regularly show strong support for the homicide bombings, though it has come down a bit in recent months, following the strong Israeli military response.

A poll released last week by a Palestinian think tank showed support for homicide bombings dropped from 74 percent in December to 68 percent recently. The survey, which had a margin of error of 3 percentage points, was roughly in line with other polls.

Ghassan Khatib, who headed the think tank and was recently named Labor Minister, said the modest decline in support for bombings was due to three reasons: international criticism of the Palestinians, the damage done to the Palestinian image by the bombings, and the consequences for the Palestinians, including Israel's military responses.

He said the newspaper ad was the strongest public expression to date opposing the bombings.

Hamas, the group that has carried out more attacks than any other, dismissed the ad as the work of a small number of Palestinians who lack broad support.

"Let's see how much support they will have among the people," Hamas spokesman Abu Shanab said.

The bombings "really hurt Israel. It really affects the Israelis, and if we have an effective weapon in our hands and the whole world is trying to take it off us, this kind of reaction shows it to be the most effective way," Abu Shanab added.

The Palestinian leadership routinely condemns the bombings, but the Palestinian security forces have not carried out large-scale roundups of suspects in Hamas or other groups behind the attacks.

Most attacks have been carried out by young Palestinian men. Initially, most had strong links to radical Islamic movements, such as Hamas and Islamic Jihad. But recently, their numbers have also included members of secular groups, such as the Al Aqsa Martyrs Brigade, which is linked to Arafat's Fatah movement.

Ahmed Abdel Rahman, a longtime aide to Arafat, acknowledged that Palestinian public opinion was at odds with the stance of the Palestinian leadership. He said the best way to end the bombings was for a resumption of peace talks, which broke down 18 months ago amid the violence.

"You can say that (Palestinian) public opinion is with these operations," Abdel Rahman said. "But the Palestinians still consider Arafat their leader. The solution is to stop these suicide operations with a political solution."

But Jibril Rajoub, the Palestinians' West Bank security chief, said the Palestinians cannot cooperate with Israel now to arrest those behind homicide attacks.

"As long as the Israelis are continuing their invasion — using their tanks, F-16s and Apaches (attack helicopters) — there will be no arrests of any Palestinian," Rajoub said from Egypt, where he was meeting with officials about Palestinian security matters.

A number of prominent Islamic figures have endorsed homicide bombings.

Hamed Baitawi, chief of the Islamic Clergy Committee in Palestine, has close ties to Hamas and said homicide attacks were legitimate.

"Islam demands that we avoid killing women, children and civilians, but God ordered us to fight our enemy in the same way that he fights us," Baitawi said. "As long as the Israeli occupation is killing our people, we have the right from the sky to kill its civilians."

But Zohair Dobei, considered a moderate Muslim sheikh in the West Bank city of Nablus, stressed the Islamic prohibition on killing civilians. He also was critical of Palestinian mothers who have appeared in videos, endorsing bombing attacks carried out by their sons.

"I can't imagine that there is a mother in the world who can dispatch her son, or who would not prevent him from doing so if she knows that he is going to kill himself," Dobei said.