"We are announcing a series of revenge operations called 'An Eye for an Eye.' Your Alawite villages will pay a very dear price for every chemical rocket that you've launched against our people."
According to Syrian state-run television's depiction of events, government forces came across the site of the gas attack when they entered the rebel stronghold of Jobar on the edge of Damascus. The bodies of some of those killed in the attack early Wednesday had been found there.
Several of the soldiers were "suffocating" from exposure to gases as they entered the city, according to state TV.
"It is believed that the terrorists have used chemical weapons in the area," Syrian TV reported, citing an anonymous source. The government uses the term "terrorists" to describe rebel forces.
Broadcast video showed a room containing gas masks, gas canisters and other paraphernalia that could be used in a gas attack. The army said it uncovered the cache in a storage facility in Jobar. CNN could not independently confirm the authenticity of the video.
"We said it from the first moment and, here, we assure again that we have never used chemical weapons (around Jobar) or any other region in any form whatsoever -- ... liquid, gas or whatever," Information Minister Omran al-Zoubi said in an interview on Lebanese television.
He blamed the rebels.
The rebels say that government forces fired rockets into the heavily populated civilian area. Opposition spokesman Badr Jamous from the Syrian National Coalition claimed that some of the rockets delivered chemical payloads.
More than 1,300 people were killed, most of them by gas, said Khaled al-Saleh, another spokesman for the group.
Al-Saleh said that medical teams in the affected area had administered 25,000 shots of atropine -- a medication used to treat people exposed to the nerve gas sarin -- after the attack.
Doctors Without Borders said three hospitals it supports in Syria's Damascus governorate reported having received some 3,600 patients displaying neurotoxic symptoms last Wednesday morning.
"The reported symptoms of the patients, in addition to the epidemiological pattern of the events -- characterized by the massive influx of patients in a short period of time, the origin of the patients, and the contamination of medical and first aid workers -- strongly indicate mass exposure to a neurotoxic agent," said Dr. Bart Janssens, director of operations.
Video showed rows of bodies without apparent injury, as well as people suffering convulsions or who appeared to be struggling to breathe.
CNN could not verify where or when the videos were recorded, and could not confirm the number of casualties.