Iraqi Prime Minister Nouri al-Maliki called on lawmakers on Sunday to withdraw confidence from one of his deputies, as the country's political crisis deepened with U.S. forces completing their withdrawal.

Maliki's push for the ouster of Saleh al-Mutlak, a Sunni Arab who described him on television as "worse than Saddam Hussein", came a day after the deputy prime minister's Iraqiya bloc said it was boycotting parliament in protest at the premier's alleged centralization of power.

An explosion hit an Egyptian pipeline feeding gas to Israel and Jordan on Sunday in the 10th such attack this year, Egyptian security services said.

The blast struck south of the town of el-Arish in the north of the Sinai peninsula and targeted a segment of pipeline which was gas-free as it was under repair.

Leaders of the wealthy Gulf Arab states will meet at their annual summit in Riyadh on Monday, against a backdrop of accelerating regional turmoil and fears of growing Iranian influence after the U.S. pullout from Iraq.

"Several regional issues impose themselves on the summit this year," including relations with Iran as well as the situation of Syria and Yemen, the Omani minister for foreign affairs, Yussef ben Alawi Abdullah, told Agence France Presse.

Twenty civilians and six regime soldiers were killed in violence in Syria on Sunday as clashes raged between deserters and regular army troops in centers of protest against the regime, human rights activists said.

Security forces shot dead 20 civilians across the country, the Local Coordination Committees, the main activist group spurring protests on the ground, reported.

The rival Palestinian movements Fatah and Hamas began meeting in Cairo on Sunday to discuss ways of implementing a stalled reconciliation deal, an official said.

Delegates from the two factions met "to prepare for the comprehensive dialogue" which is to take place on Tuesday in the Egyptian capital, Azzam al-Ahmed, head of the Fatah delegation told Agence France Presse.

Troops and protesters clashed Sunday in Cairo for the third straight day, pelting each other with rocks in skirmishes near parliament in the heart of the Egyptian capital.

At least 10 protesters have been killed and 441 others wounded in the three days of violence, according to the Health Ministry. Activists say most of the 10 fatalities died of gunshot wounds.

Israel was on Sunday preparing to release 550 Palestinian prisoners who will be freed after nightfall to complete a swap deal which brought about the release of captive soldier Gilad Shalit.

The release operation was expected to take place late in the evening, when the prisoners would be bussed to drop-off points near the West Bank city of Ramallah and along the Gaza border.

Israel and the United States are determined to prevent Iran from obtaining nuclear weapons and do not rule out any option to that end, Israel's defense minister said on Sunday.

"Our two countries clearly believe that a nuclear Iran is neither conceivable nor acceptable and we are determined to prevent Iran from getting nuclear weapons," Defense Minister Ehud Barak told public radio, two days after meeting U.S. President Barack Obama.

Two Kuwaiti journalists who were detained in Iran for more than a month on spying charges returned home on Sunday after being freed, the Gulf emirate's media reported.

Adel al-Yahya, a presenter for private satellite television channel al-Adalah, and freelance cameraman Raed al-Majed flew in on a special flight ordered by the Kuwaiti emir, the al-Watan daily reported on its website.

The last U.S. soldiers rolled out of Iraq across the border to neighboring Kuwait at daybreak Sunday, whooping, fist bumping and hugging each other in a burst of joy and relief. Their exit marked the end of a bitterly divisive war that raged for nearly nine years and left Iraq shattered, with troubling questions lingering over whether the Arab nation will remain a steadfast U.S. ally.

The mission cost nearly 4,500 American and well more than 100,000 Iraqi lives and $800 billion from the U.S. Treasury. The question of whether it was worth it all is yet unanswered.