MASNAA, Lebanon — Syrian security forces killed as many as 20 Lebanese gunmen who were fighting alongside rebels in Syria on Friday, raising tensions amid mounting fears that the Syrian civil war is inflaming the region.
Lebanese security officials said the gunmen were killed as they tried to enter the Syrian town of Tal Kalakh, near the Lebanese border. The officials asked that their names not be used because they were not authorized to speak publicly.
Syrian state-run media also reported that Lebanese gunmen were killed. But the SANA report said there 17 — not 20 — fighters. The discrepancy could not immediately be reconciled.
The Lebanese gunmen were Sunni Muslims, as are the vast majority of Syria’s rebels. Syrian President Bashar Assad — along with his most elite troops — belong to the Alawite sect, an offshoot of Shi’ite Islam.
Lebanon is particularly vulnerable to getting sucked into the conflict in Syria. The countries share a complex web of political and sectarian ties and rivalries that are easily inflamed. Lebanon, a country plagued by decades of strife, has been on edge since the uprising in Syria against Assad began in March 2011, with deadly clashes between pro- and anti-Assad Lebanese groups erupting on several occasions.
The deaths came as rebels have tried to close in on the Syrian capital, Damascus, in recent days.
On Friday, Syrian soldiers fought rebels in and around the capital as Internet and most telephone lines were blacked out for a second day. But the intense battles around the country’s international airport appeared to have calmed.
The airport road had reopened by Friday and the head of the Syrian Civil Aviation Agency, Ghaidaa Abdul-Latif, said the airport was operating ‘‘as usual.’’ A day earlier, heavy fighting forced the closure of the road and airlines canceled international flights to Damascus.
The Britain-based Syrian Observatory for Human Rights and residents who were interviewed while leaving Syria on Friday said there was still sporadic fighting in pockets of the capital and on the outskirts.
A minibus driver said he heard explosions in the distance as he drove through Damascus.
‘‘There are extreme security measures in Damascus today,’’ said the driver, who asked to be identified only by his first name, Mohamad, out of fear for his personal safety.
‘‘We were stopped at several checkpoints,’’ he told the Associated Press. ‘‘Our IDs were checked and they even opened all the bags and suitcases.’’
The communications blackout has raised fears of an explosion of fighting outside the public gaze. The Internet has been a key tool of activists over the course of the Syrian conflict, which started 20 months ago and has left more than 40,000 people dead, according to activists.
Syrian authorities previously have cut Internet and telephones in areas ahead of military operations. On Friday, some land lines were working sporadically.
In the southern part of the capital, the main road to Damascus’ airport reopened early Friday afternoon, according to the Observatory. Intense clashes broke out after midnight in villages and towns near the facility but the area was calm by the late morning, the group said. It said rebels were able to destroy several army vehicles near the airport.
The Observatory, which has a network of activists around Syria, reported fighting in other southern neighborhoods of Damascus, including Tadamon and Hajar Aswad
The group said it was able to contact its sources who used satellite telephones.
According to the Observatory and witnesses who crossed into Lebanon, several suburbs — including Aqraba, Beit Saham, and Daraya — also saw heavy fighting.
By contrast, a man who crossed into Lebanon with his wife and son said it was quiet Friday nearby in Damascus’ western suburb of Zabadani — a far cry from a day earlier, when the neighborhood was ‘‘like hell.’’