That stalemate suggests the war will not end soon. The U.N. said Wednesday that more than 60,000 people have been killed since March 2011 a figure much higher than previous opposition estimates.
Rebels took control of Douma, a suburb of some 200,000 located nine miles (15 kilometers) northwest of Damascus, in mid-October 2011, after launching attacks on military posts throughout the city, activists said.
Less than a week later, the rebels had taken over a half-dozen checkpoints and government buildings, said activist Mohammed Saeed. The army withdrew from others.
"Since then, the city has been totally liberated," he said. "There are no government troops left, but we still suffer from regime airstrikes almost every day."
Today, those entering Douma must pass through rebel checkpoints at the city's main entryways. Rebels with camouflage vests and Kalashnikov rifles zip about on motorcycles, communicating by walkie-talkie. Some belong to the security brigade, an improvised police force to catch looters that works with a judicial council of Muslim clerics and lawyers who run a prison.
In November, residents formed a civilian council to provide services for the estimated one-third of Douma's residents who have not fled the violence.
The council oversees committees for medical issues, bakeries, media relations and other tasks, said its head, Nizar Simadi. A former cleaner at city hall runs a cleanup crew that helps remove rubble from the streets after shell attacks and airstrikes.
The city's electricity went out in November activists accuse the government of cutting it in revenge but former electric company employees have strung in power from nearby areas still on the government network, returning power to some of the city.
Douma has more than a dozen rebel brigades, and the city's fighters have joined battles in many other areas around the capital. Most of their support comes from wealthy Syrians abroad who send money to buy arms, said the head of one rebel brigade, the Douma Martyrs, who goes by the name Abu Waleed.
In November, Douma's fighters raided two army bases in the nearby suburb of Otaya, he said, making away with arms that helped them push closer to Damascus. But they can do little about the government's airstrikes.
Rebel forces are currently fighting the government in areas on three sides of the capital. They are closest in the south, where they have pushed into the poor Damascus neighborhood of Hajar al-Aswad. Recent weeks have also seen fierce clashes in the southwestern suburb of Daraya, which the government says it is close to reclaiming.
During Thursday's airstrikes on Douma, a government fighter jet launched two bombing runs on a densely populated residential area near a prominent mosque, said Saeed, the activist.
Videos posted online showed residents rushing though a smoke-filled street and loading wounded people into cars and pickup trucks. One man was buried up to his thigh in debris and helped rescuers dig himself out. Another man emerged from a pile of rubble with blood on his face and covered head-to-toe in gray cement dust.
One group provided videos of 12 people they said were killed in the attack. The videos appeared genuine and corresponded to other AP reporting on the strike.
The Britain-based Syrian Observatory for Human Rights said at least 10 rebel fighters and 32 civilians were killed Thursday in clashes, shelling and airstrikes in the Damascus Countryside province that surrounds the capital, more than anywhere else in Syria.
Late Thursday, a car bomb exploded at a gas station inside the city itself, killing at least nine people, activists said. Syria's state news agency blamed the attack on "terrorists," its shorthand for the rebels, but did not give numbers for the dead and wounded. There was no immediate claim of responsibility.
Despite rebel advances near Damascus, it remains unclear whether they'll be able to turn the tables on Assad's forces. Rebels launched a hasty offensive on Damascus last summer but were swiftly routed by government forces.
Before attempting to take Damascus again, Saeed said the rebels must gather enough ammunition to sustain the battle, take over nearby army bases to prevent attacks from behind and increase coordination between rebel brigades.
He guessed that could take six months.
The Syrian government has not commented on the fall of Douma to rebels, whom it characterizes as terrorists backed by foreign powers seeking to destroy the country.
The chief of staff of Syria's armed forces called on the army to continue its "holy and national task to crush the armed terrorist groups and their hideout," the state news agency reported.
Gen. Abdullah Ayoub said the "conspiracy" against Syria would fail "thanks to the bravery of the Syrian army and the coherence of the Syrian people."
Activists reported clashes in a number of other parts of Syria on Thursday, including inside the Taftanaz helicopter base in the north.
In Jordan, the U.N. refugee agency said that around 1,200 people have fled across Syria's southern border each day for the past three days, an increase reflecting fresh violence in the south. UNHCR reporting officer Danita Topcagic said many shops in the area were shut, making it hard for people to find food, and that electricity and water supplies were short.
About a half-million Syrians have sought refuge from the war in neighboring countries, and many more are displaced inside Syria.
Meanwhile, the parents of an American journalist who has been missing in Syria since he was kidnapped Nov. 22 appealed to his captors for compassion and any information about their son's health and welfare. Thirty-nine-year-old James Foley was in the country contributing videos to Agence France-Press, which has vowed to help secure his release.
Twenty-eight journalists were killed in Syria in 2012, prompting the Committee to Protect Journalists to name Syria the most dangerous country in the world to work in last year.
Parents appeal for journalist's release
Rochester, N.H. • From their New Hampshire home, the parents of journalist James Foley, 39, who has been missing in Syria since he was kidnapped more than a month ago appealed to his captors for compassion and any information about their son's health and welfare. John and Diane Foley pleaded for his safe return. "I appeal to the people who have Jim to let us know where he is and to help us secure his release," John Foley said. "We just pray that he's released." The Committee to Protect Journalists has named Syria the most dangerous country in the world in which to work.