An aide to President Mahmoud Abbas on Monday said talks on forming a Palestinian unity government have been suspended, the latest setback in drawn-out efforts by the rival Hamas and Fatah movements to establish a coalition acceptable to the West.

It wasn't clear whether the suspension was the sign of a real crisis or simply a negotiating tactic by Abbas' weakened Fatah party.

Abbas has been pushing Hamas to enter a unity government in hopes of ending an international aid boycott against the Palestinian government. The sanctions were imposed after Hamas defeated the more moderate Fatah in legislative elections early this year, putting the Islamic militant group in control of the Palestinian parliament and Cabinet while the moderate Abbas retained his position as president.

After months of negotiations, participants had reported progress in recent days, raising hopes that a deal was near. In a breakthrough, the sides agreed on a candidate for prime minister, settling last week on a U.S.-educated professor who has good relations with Hamas and Fatah.

But Abbas aide Nabil Amr said Monday that the talks had reached a standstill.

"We would say talks are suspended now," he told a news conference. "What we have agreed upon is only the first mile over the 1,000-mile road."

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Abbas has met repeatedly over the last week with Prime Minister Ismail Haniyeh of Hamas to discuss the distribution of government portfolios between their parties, most recently a late-night session that ended early Monday.

Fatah officials have accused Hamas of being unreasonable in demanding control over the powerful finance and interior ministries. The next finance minister would be in charge of persuading the international community to resume aid, while the interior minister oversees security forces.

After Amr's announcement, Hamas officials quickly denied any serious trouble, raising the possibility that Fatah had stepped away as a negotiating tactic.

"I want to reassure our people that the negotiations are continuing and they have not been halted," Haniyeh said. "Talks are continuing on the highest levels."

Still, negotiators described serious differences. "We must not fool anyone. There were stumbling blocs at the last minute," said Nabil Abu Rdeneh, a spokesman for Abbas.

Negotiators said the main committee working on the division of Cabinet portfolios had stopped meeting, and Abbas planned to leave Gaza for a trip to Saudi Arabia.

Abbas, who was elected separately, hopes the emergence of a unity government will help end international sanctions and allow him to restart peace talks with Israel.

Israel and Western donors have demanded Hamas renounce violence, recognize Israel's right to exist and accept past peace agreements. Hamas, which is committed to Israel's destruction despite its stated offer of a long-term truce, rejects the conditions.

Under the emerging coalition deal, the current Hamas-led government would be replaced with a Cabinet of independent experts. The government would focus on domestic issues, like education and road building, while Abbas would be responsible for dealing with Israel.

Relations with Israel have deteriorated since Hamas took office, especially after Hamas-linked militants captured an Israeli soldier in a cross-border raid last June.

Israel has been carrying out a military offensive in the Gaza Strip since the kidnapping, while Palestinian militants continue to fire homemade rockets into southern Israel.

U.N. High Commissioner for Human Rights Louise Arbour kicked off a five-day trip to the region Monday, assuring residents of an embattled Palestinian neighborhood in Gaza "that the world has not abandoned them."

Arbour began her visit with a tour of a residential neighborhood in Beit Hanoun, where 19 members of an extended family were killed this month in an errant Israeli artillery attack.

A large crowd quickly gathered around Arbour, showing her pictures of dead and wounded relatives and calling for punishment of Israeli soldiers responsible for the attack.

Arbour urged Israeli and Palestinian leaders to stop the "cycle of violence" and do more to protect civilians.

"I'm basically here to express my concern and bring some comfort, I hope, by showing these victims that the world has not abandoned them," Arbour said. "I think we can't continue to see civilians who are not the authors of their own misfortune continue to suffer to the extent of which I see."

As she spoke, Israeli bulldozers tore through nearby fields that the army said are used by militants to fire rockets. The Israeli operation took place in another part of town, and did not directly affect Arbour's visit.

In nearby Beit Lahiya, dozens of residents crowded around the home of a Hamas militant to prevent Israel from carrying out an airstrike on the building.

The crowd volunteered to serve as human shields after the homeowner received an order from the army that it planned to destroy the site, residents said. It was the third time in recent days that a Palestinian crowd has forced the army to call off an airstrike.

Despite the ongoing Israeli crackdown, Palestinian militants fired a total of seven rockets Monday. No injuries were reported. Last week, an Israeli woman was killed in a rocket attack.