Speaker Nabih Berri urged Iraq and Iran to limit the visits for Lebanese Shiites pilgrims to the holy sites in those two countries to flights by air.

An Nahar newspaper reported on Friday that the speaker contacted Iraqi Ambassador to Lebanon Omar al-Barzanji and Iranian Ambassador Ghazanfar Roknabadi to demand them to halt all visits by land.

As one diplomatic effort after another fails to end more than a year of brutal violence in Syria, the Obama administration is preparing a plan that would essentially give U.S. nods of approval to arms transfers from Arab nations to some Syrian opposition fighters.

The effort, U.S. officials told The Associated Press, would vet members of the Free Syrian Army and other groups to determine whether they are suitable recipients of munitions to fight the Assad government and to ensure that weapons don't wind up in the hands of al-Qaida-linked terrorists or Hizbullah that could target Israel.

The rebel Free Syrian Army said on Thursday it is making "every effort" to locate and release a group of Lebanese Shiite pilgrims kidnapped in Syria's northern province of Aleppo.

"The leadership is making every effort to find out where the abductees are, and to make sure they are freed," FSA official spokesman Colonel Qassem Saadeddine said in a statement.

Syria's embattled President Bashar Assad said on Thursday his government is capable of finding a way out of the crisis gripping his country, as he met with a visiting Iranian government minister.

"Syria has been able to overcome the pressures and threats it has faced for years and is able to get out of this crisis thanks to the strength of its people and commitment to unity and independence," Assad said, quoted by SANA state news agency.

The Syrian army and security forces have been responsible for the majority of the serious rights abuses committed since March this year as they hunt down defectors and opponents, U.N.-appointed investigators said on Thursday.

"Most of the serious human rights violations documented by the Commission in this update were committed by the Syrian army and security services," said the Independent Commission of Inquiry on Syria, established by the U.N. Human Rights Council last year to investigate abuses there since the crackdown.

Syrian regime forces pounded the town of Rastan in central Homs province on Thursday, killing three civilians, said the Syrian Observatory for Human Rights.

Violence elsewhere in Syria killed 10 other people in the morning, the Britain-based watchdog reported, including four who were summarily executed in northwestern Idlib province.

The United States condemned on Thursday the abduction of Lebanese men in the Syrian province of Aleppo, saying the abduction of people along sectarian lines is unacceptable.

“We condemn the kidnapping of Lebanese citizens in Aleppo and call for their immediate release,” the U.S. embassy in Lebanon said on its twitter feed.

The United States urged Lebanese political parties on Wednesday to exercise restraint following deadly fighting between pro- and anti-Syrian groups.

“We call on all political actors in Lebanon to exercise restraint and respect for Lebanon’s security and to respect the rule of law,” said State Department spokeswoman Victoria Nuland.

Foreign Minister Adnan Mansour stressed on Thursday that contacts are ongoing to release Lebanese men kidnapped in the Syrian province of Aleppo.

“The President, Speaker and Prime Minister are following up the incident with the competent authorities, but it needs time,” Mansour told Voice of Lebanon radio (93.3).

The head of Syria's main opposition bloc, Burhan Ghalioun, formally resigned from his post, a statement issued by the Syrian National Council said Thursday after a two-day meeting in Istanbul.

The SNC "office decided to accept the resignation and to ask the council president to pursue his work until the election of a new president at a meeting on June 9-10", it said.