The discovery came after the government forces surrounded a sector of militant-held district of Jobar on Saturday.
“Army heroes are entering the tunnels of the terrorists and saw chemical agents,” Syria television said, adding, “In some cases, soldiers are suffocating while entering Jobar.”
It added that ambulances arrived in the region to rescue the people who were suffocating in Jobar and the area is now controlled by Syrian army forces.
The Syrian government also stated that the foreign-backed militants had carried out the recent chemical attack in Damascus suburbs of Ain Tarma, Zamalka and Jobar.
On Wednesday, Syria’s opposition claimed that hundreds were killed in a government chemical attack on militants strongholds in Damascus suburbs of Ain Tarma, Zamalka and Jobar before dawn.
The Syrian army has vehemently denied allegations that it used chemical weapons against militants in the suburbs of the Ghouta region, saying the accusations were fabricated to distract the visiting team of UN chemical weapons experts and to cover up militants losses.
Meanwhile, UN Under-Secretary-General Angela Kane arrived in Damascus on Saturday for talks aimed at establishing an investigation into the Wednesday’s attack.
In a related development, Russian Foreign Ministry on Friday accused Syria’s opposition of preventing an objective probe into the alleged attack.
US Defense Secretary Chuck Hagel, however, said his commanders have prepared a range of options for President Barack Obama if he chooses to go for military action against Syria.
“The Defense Department has a responsibility to provide the president with options for contingencies, and that requires positioning our forces, positioning our assets, to be able to carry out different options – whatever options the president might choose,” he said.