BEIRUT (AP) -- Syrian rebels fighting to topple President Bashar Assad set their sights Friday on the capital's international airport in a bid to cut off the regime's supplies, clashing with government troops nearby and again forcing the closure of the airport road.
A fighter who is part of the push against Damascus International Airport declared it a legitimate target, claiming that the regime has stationed troops and elite forces there as well as military planes that transport ammunition.
Losing control of the airport would be a major blow to the regime, which has recently lost two air bases near the capital.
It was unclear just how close to the airport, a few kilometers (miles) south of the capital, the battles reached. Fighting has intensified in the past week in the southern districts of the Syrian capital and its suburbs.
"The rebels have made major military gains, and have been fighting closer to the regime's nerve center, which is the airport, for days, systematically chipping away at the political and military power off the Assad regime," said Fawaz A. Gerges, head of the Middle East Center at the London School of Economics.
The clashes around Damascus, a city of 1.7 million, have already forced the suspension of commercial flights over the past week, although airport officials insist the facility remains open and was functioning normally on Friday.
Rebels said they were targeting the airport in an effort to cut military supplies to the government.
"This would send a very strong political message to the regime. It will be a moral victory, to say the least," said the fighter, who gave only his first name, Nour, for security reasons. "The battle to cut off the regime supplies from the airport has started."
Another rebel, speaking on condition of anonymity for the same reason, said the airport is now considered a "military zone."
"We urge civilians to stay away," said the rebel, a member of the Damascus area military command involved in Friday's fighting.
Iran and Russia are widely believed to be supplying the Assad regime with weapons through the airport.
Tehran has not given details of its direct military aid to Assad's regime but has acknowledged that Revolutionary Guard envoys have been advisers in the past.
Moscow has rejected Western sanctions against Assad's regime and said it would honor earlier signed weapons contracts with Syria for the delivery of anti-shipping and air defense missiles. The Kremlin insists that the Russian arms sales don't violate any international agreements.
At talks in Belfast, Northern Ireland, U.S. Secretary of State Hillary Rodham Clinton said Friday that the United States and Russia are committed to trying again to get Assad's regime and the rebel opposition to talk about a political transition, setting aside a year and a half of U.S.-Russian disagreements that have paralyzed the international community.
Clinton stressed, however, that the U.S. would insist once again that Assad's departure be a key part of that transition, a position not shared by the Russians.
On Friday, Syrian government forces were firing rockets and mortars at suburbs south of Damascus amid heavy clashes with rebels, according to activists. Most of the fighting was taking place in the towns of Aqraba and Beit Saham near the airport.
An airport official said the highway leading to the facility was closed Friday because of the fighting. The official said, however, that the airport was functioning as normal and that people were reaching it through side roads.
The official declined to be identified because he was not authorized to give official statements.
Meanwhile, video posted online by activists showed rebels with a helicopter they claim to have captured from the Syrian army in an air base outside of Damascus.
"Your days are few, run away because we are coming to you, Bashar," one of the rebels is heard saying on the video that was posted Friday. The activist video appeared genuine and in line with Associated Press reporting.
The fresh violence around the capital, including near the airport, comes amid growing international concerns about the use of chemical weapons in the civil war.
Syria has not confirmed it has non-conventional weapons, and insists it would never use such arms against its own people. U.S. officials say intelligence suggests the government does have the weapons and has moved some of its stockpiles in recent days.
U.N. Secretary-General Ban Ki-moon renewed a call for Syria not to use chemical weapons, saying Friday the move would amount to an "outrageous crime" against humanity.
Speaking to reporters after visiting Syrian refugee camps in Jordan and Turkey, he also called for an end to the violence.
"The slaughter in Syria must stop," Ban said. "The military path is a dead end. It only fills the streets with more blood."
Associated Press writers Zeina Karam in Beirut, Albert Aji in Damascus, Suzan Fraser in Ankara and Mike Corder in the Netherlands contributed to this report.