By Khaled Yacoub Oweis
AMMAN (Reuters) - At least 20 people were killed on Monday in air raids and rocket barrages on opposition strongholds in Damascus to halt a flow of rebel fighters into the capital, activists and opposition military sources said.
The bombardment, which concentrated on the north and east of Damascus and on the nearby suburb of Douma, a rebel stronghold, is among the heaviest in the capital since the uprising against President Bashar al-Assad began two years ago, they said.
Ten rebels also were killed in fighting in Adra, a contested residential and industrial town between Douma and Damascus where several army and intelligence compounds are located, and in the suburb of Harasta on the main highway north.
Video footage showed a bulldozer clearing rubble from a collapsed building in Douma, where activists said a child and two women were among those killed in an air raid by a Syrian MiG warplane and by multiple rocket rounds that hit the conservative Sunni Muslim suburb.
Douma and other Sunni working class towns that ring Damascus have been at the forefront of the revolt.
"It seems that the regime has gotten a shot of adrenaline. The bombing is very heavy but the situation on the ground does not appear to be changing," an activist in the neighbourhood of Qaboun said. Two women and one man were reported killed in another air raid there.
Opposition fighters who control large parts of Qaboun have been fighting loyalist forces, the activist said.
A rebel commander in Damascus who uses the alias Abu Hamza said opposition fighters based in eastern Ghouta, an expanse of built-up areas and farmland on the edge of Damascus, were moving to the inside of Damascus, especially to the neighbourhoods of Qaboun and Barzeh, to minimise the possibility of chemical weapons being used against them.
"A good number of fighters have been moving to Qaboun and Barzeh. The thinking is that Assad would not use chemical weapons in such close quarters because he would harm his own forces," he said.
Activists reported at least two instances where the army used chemical weapons during attacks on rebels in eastern Ghouta in the last few weeks.
There was no independent confirmation of the attacks, which followed the death of 26 people in a rocket attack near the city of Aleppo. The authorities and rebels accused each other of firing a missile there carrying a load of chemicals.
While rebel brigades have been encroaching on Damascus, opposition sources say they lack the firepower to dislodge Assad's forces from fortress-like security compounds and army installations that dot the inside the city.
Assad's core forces, who mostly belong to his minority Alawite sect, an offshoot of Shi'ite Islam that has controlled Syria since the 1960s, is also dug in the imposing Qasioun mountain, which is part of Damascus.
At least 70,000 people have been killed in the conflict, which began with peaceful demonstrations two years ago against four decades of rule by Assad and his late father, President Hafez al-Assad.
(Editing by Michael Roddy)