U.S. forces held a formal ceremony to lower the flag in Iraq on Thursday, ahead of their withdrawal from the country nearly nine years after the controversial invasion to topple Saddam Hussein.

The ceremony marking the closure of the U.S. military's headquarters near Baghdad comes after U.S. President Barack Obama hailed the "extraordinary achievement" of the war in a speech to welcome home some of the troops.

Iraq will send a delegation to Syria to try to convince Damascus to implement a Baghdad initiative to end months of bloody conflict, Prime Minister Nouri al-Maliki said on Thursday.

"When I arrive in Baghdad, I will hold a meeting to prepare the plans to send a delegation to Syria in order to implement the Iraqi initiative," Maliki told Agence France Presse as he flew back to Iraq from Washington.

Vandals tried to set light to a mosque in a West Bank village overnight, the local mayor told Agence France Presse on Thursday in what was the latest "price tag" vengeance attack.

"Carpets and chairs in the women's section were partly burnt and on the wall was Hebrew graffiti saying 'The war has started'," said Abdelkader Abdeljalil, mayor of Burqa village, which lies several kilometers (miles) east of Ramallah.

Syrian army deserters killed at least 27 soldiers and members of the security forces during clashes in the southern province of Daraa on Thursday, a rights group said.

The fighting broke out at dawn at checkpoints in three separate locations, the Britain-based Syrian Observatory for Human Rights said in a statement.

Syrian military commanders have ordered troops to indiscriminately shoot at unarmed protesters, Human Rights Watch said in a report released Thursday based on interviews with former soldiers who defected.

The defectors named 74 military and intelligence officers "who allegedly ordered, authorized, or condoned widespread killings, torture, and unlawful arrests," the rights group said in a statement.

The Russian and Iranian leaderships are trying to mediate between the Syrian officials and the Muslim Brotherhood leadership to resolve the Syrian crisis away from any military intervention, As Safir newspaper published on Thursday.

Syrian President Bashar Assad “is seriously seeking a political solution,” Lebanese Muslim officials told the daily.

The first congress of the Syrian National Council, the opposition's most representative grouping, will open in the Tunisian capital on Friday, an official said.

The three-day meeting will be attended by SNC leader Burhan Ghalioun and about 200 other members, the outfit's Tunis representative Abdullah Terkmani said on Wednesday.

Members of the international peacemaking Quartet appeared to make little progress on Wednesday after separate talks with Israeli and Palestinian officials in a bid to kick-start stalled peace talks.

Envoys and Quartet representative Tony Blair "stressed the important objective of a direct exchange between the parties without delay or preconditions," a statement from the diplomatic grouping read.

The United States portrayed Syrian President Bashar al-Assad's regime as "dead men walking" on Wednesday, and urged Russia, China and India to put politics aside to stand with the West on action against the regime.

"Our view is that this regime is the equivalent of dead men walking," State Department special coordinator on Middle East affairs Frederic Hof told U.S. lawmakers in a hearing on U.S. policy toward Damascus.

U.N. leader Ban Ki-moon said Wednesday that the international community must now act against the Syrian government's crackdown on protests "in the name of humanity."

Ban told a press conference he has sent a U.N. Human Rights Council report on the Syrian regime's crackdown to the U.N. Security Council. This could increase pressure on the 15-nation council to act even though Russia and China vetoed a resolution on the crisis in October.