DAMASCUS, Syria (AP) -- Syrian army troops on Wednesday killed 175 rebels, many of them al-Qaida-linked fighters, in an ambush described as one of the deadliest attacks by government forces against fighters near Damascus, according to state media.
An opposition group said the dawn ambush -- part of a government effort to secure the capital -- was carried out by the Lebanese Hezbollah group, which has been instrumental in helping President Bashar Assad's regime push back rebels entrenched in the suburbs of the capital city.
Syrian state news agency SANA quoted a field commander in the eastern Ghouta area as saying most of the rebels killed in the assault near Oteibah lake southeast of Damascus belonged to the al-Qaida-linked Nusra Front rebel group. The report said several of those killed were foreign fighters who came to Syria from Saudi Arabia, Chechnya and Qatar.
SANA said the operation dealt "a smashing blow to terrorists," a term Syrian state media uses for rebels.
The agency posted several photographs on its website showing dozens of bodies of men, some with leg wounds, lying in a dirt track of an open field. Some were wearing fatigues, but most wore civilian clothes and appeared to have been carrying bags of clothes and bottles of water that were scattered on the ground, suggesting they were changing locations when they were ambushed.
The Britain-based Syrian Observatory for Human Rights said at least 152 rebels were killed, most of them Nusra Front and other fighters from Islamic brigades. "This is the heaviest loss for Nusra Front and Islamic brigades since the start of the revolution," said Rami Abdurrahman, director of the rights group.
The Observatory, which has been documenting Syria's nearly three-year conflict by relying on activists' reports on the ground, said Hezbollah fighters backed by Syrian troops carried out the ambush. Few other details emerged.
Reinforcing that report, Hezbollah's Al-Manar TV aired exclusive footage of what it said was the ambush, showing at least two large bombs that were detonated along the route used by the opposition fighters.
From a distance, people could be seen running in different directions following the blasts.
An army colonel told the Lebanon-based Al-Mayadeen channel that his troops acted on intelligence and the rebels lost "more than 150 men." Syrian army tanks and armored personnel carriers were seen in the broadcast, as were soldiers patrolling on foot.
Syria's pro-government Al-Ikhbariya channel aired its own footage of the aftermath, showing soldiers milling about as dozens of bodies of rebels lay scattered on the ground. The station also broadcast images of what it said were rebels' weapons, confiscated by the army.
In a similar operation near Damascus in August, Syrian troops ambushed a group of rebels, killing more than 60 opposition fighters on a desert road northeast of the capital.
Syria's conflict started as largely peaceful protests against Assad's rule in March 2011. It has developed into a civil war that has taken on increasingly sectarian overtones, pitting mostly Sunni Muslim rebels against Assad's government, which is dominated by Alawites, a sect in Shiite Islam.
More than 140,000 people have been killed, activists say, and millions have fled their homes to seek shelter in neighboring countries or in safer parts of their homeland. Many refugees have settled temporarily in areas sealed off by Assad's troops, with little if any food or medical aid within reach.
In Damascus, Assad met Wednesday with Alaeddin Boroujerdi, head of the influential Iranian parliamentary committee on national security and foreign policy, who appealed for a political solution to the conflict.
At a news conference, Bouroujerdi said he discussed the latest military developments with Syrian officials.
Meanwhile, the international mission to rid Syria of its chemical weapons by June 30 said that a batch of sulfur mustard, widely known as mustard gas, was shipped out of the country Wednesday.
Sigrid Kaag, head of the joint operation by the U.N. and the Organization for the Prohibition of Chemical Weapons, called for Syria to continue its efforts to relinquish its arsenal "in a safe, secure and timely manner, through systematic, predictable and high-volume movements."
The mission to eliminate Syria's chemical stockpile said the Assad government has missed at least two deadlines in the past two months to remove chemicals. The United States has accused Damascus of using stalling tactics.
According to a U.N. diplomat, the Syrian government put forward a timetable to remove all chemicals by the end of May, and the OPCW made a counter-proposal to get all chemicals out by the end of March. The government came back with a proposal to remove chemicals from all but two sites by mid-April and the other two by the end of April, and talks are continuing, the diplomat said, speaking on condition of anonymity because these negotiations have been private.
Kaag is scheduled to brief the U.N. Security Council on the latest developments on March 5, the diplomat said.
Also Wednesday, Chris Gunness of the UNRWA relief agency said a humanitarian team was permitted to work from one of its facilities in Yarmouk, a besieged Palestinian district of Damascus, for the first time since December 2012.
He called this "a highly encouraging step towards re-establishing full services and humanitarian access to Yarmouk" and said 450 food parcels were distributed "without the involvement of third parties."
Yarmouk refugee camp, which houses about 18,000 Palestinians and an unknown number of Syrians, has seen some of the worst fighting in the capital, leading to severe food shortages and widespread hunger. More than 100 people have died in camp of starvation and hunger-related illnesses, according to U.N.
U.N. Secretary General Ban Ki-Moon has urged the Syrian government to authorize more humanitarian staff to work inside the country.
Associated Press Writer Bassem Mroue in Beirut and Edith M. Lederer at the United Nations contributed to this report.