Al Jazeera has gained exclusive access to defectors from the Syrian army now allied with the country's opposition secretly operating under the noses of the government and security forces in the capital, Damascus.

"We were soldiers in the Syrian army. Our officers used to treat us very well," one member of the group, now fighting under the banner of the Syrian Free Army, said.

"But recently we had some officers from the Alawite sect, specifically from the Fourth Division. They ordered us to do things like shooting at demonstrators and mosques, specifically after Friday prayers.

"Whoever refused to carry out those orders would be shot by the officers themselves", he said.

Al Jazeera's Laurence Lee has this report.