Heavy fighting resumed near Damascus International Airport on Friday, as telephone and Internet lines remained out of service in Syria’s capital and other cities for a second day.

The Syrian opposition has made significant gains on the battlefield in recent weeks, taking over a number of military bases and downing government helicopters and jets. Some activists said the fighting near the airport could signal a rebel push to take the strategic post.

The ongoing battles, during which Syrian military jets pounded the area with bombs, led to the closure of the airport on Thursday, but an official from Syria’s Civil Aviation Authority told the Associated Press that the airport had reopened Friday afternoon.

There were also fresh signs that the Syria conflict is drawing in, and potentially destabilizing, its neighbors. In a Facebook posting, Jabhat al-Nusra, a group of Syrian Sunni extremist fighters thought to have links to al-Qaeda, reported the death Friday of 22 Lebanese fighters in the Syrian town of Tel Kalakh.

Leaders of the Lebanese Shiite militant group and political party Hezbollah have admitted in recent weeks that their fighters and commanders are in Syria but say they are not taking part directly in the conflict. Hezbollah has strongly backed the government of Syrian President Bashar al-Assad.

Interactive: Recent events in Syria

That fighters from the Lebanese Sunni community are now getting pulled into the Syrian conflict raises the possibility that clashes between the two groups could break out on Lebanese soil because of their ties to opposing groups in Syria.

In recent months, gun battles have erupted between the supporters and opponents of Assad in Tripoli, the north Lebanon town where the 22 dead fighters reportedly came from. The Lebanese army deployed in the city Friday to prevent fresh clashes.

As the unusual telephone and Web blackout continued, some Syrians expressed fears that the shutdown was a prelude to a government operation targeting civilians. The bloody war between rebels and the Syrian government has dragged on for 20 months and left more than 30,000 dead.

“We are sure they are preparing dirty games. We don’t know exactly what because it will be a military operation,” said Fadel Abdul Ghani, 36, founder of the Syrian Network for Human Rights, speaking via Skype from Damascus. “When they cut the Internet in Homs before, there was a big massacre.”

Abdul Ghani, like some other human rights workers, activists and fighters in the country, was able to keep his channels of communication open by using a satellite phone. But gathering information had become markedly more difficult since the blackout began, he said.

The Local Coordination Committees, an activist network, said at least 106 people were killed in attacks across the country Friday.

In the Turkish town of Reyhanli, just across the Syrian border about 40 miles west of Aleppo, wounded fighters, activists and aid workers said communications from within Syria had been spotty to nonexistent in the past two days.

“Of course it’s having an effect, but it’s not crucial,” said Nidal al-Aikidi, an official with the Syrian Revolution General Commission, an aid group assisting roughly 25,000 Syrians who have found refuge in Reyhanli.

About a dozen Syrian men, some of them in wheelchairs, sat beneath a tree on a busy street corner, beside a vendor selling opposition key chains and worry beads. Several fighters recuperating from their injuries said they had heard virtually nothing from their normal contacts in Syria since Thursday.

Morello reported from Reyhanli, Turkey. Ahmed Ramadan in Beirut contributed to this report.