Warplanes on Wednesday pounded suburbs of Damascus as regime forces battled rebels inching ever closer to the capital amid fears that all-out battles may break out there, a monitoring group said.
The Syrian Observatory for Human Rights, which uses a countrywide network of activists, lawyers and doctors to compile its tolls, said at least 53 people were killed on Wednesday, including some 21 in and around Damascus.
Damascus province has in recent days been the focus of clashes following a major operation launched last week by President Bashar al-Assad's forces to prevent rebels from advancing on the capital, analysts say.
Part of the battle for Damascus province is about securing the airport road, which runs southeast of the capital to Syria's main link to the outside world.
"The army has continued to pursue armed groups near the road to the international airport... killing and injuring dozens of terrorists," Al-Watan pro-regime daily said Wednesday. The government describes insurgents as "terrorists."
Warplanes blasted several towns and villages east and southwest of the city, the Observatory said.
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The watchdog also reported security force swooped on several areas in the city centre.
More than 41,000 people have been killed as the Syrian conflict approaches the 21-month mark, according to the Observatory.
In the northwest, seven soldiers were killed in "a rebel attack on a checkpoint south of Maaret al-Numan on the Aleppo-Damascus road," the Observatory said.
There was also fighting around the Wadi Deif military base, which has been under siege since rebels took Maaret al-Numan in October, it reported.
Meanwhile, owing to the violence, Hungary closed its embassy and pulled out its staff from the strife-torn country, the foreign ministry in Budapest said.
The fighting come a day after NATO approved member state Turkey's request for Patriot missiles to defend its border following a series of warnings to Damascus not to use chemical weapons.
On Monday, US President Barack Obama warned Assad against using chemical weapons, saying there would be "consequences" for such an action.