Death toll rises to 494 in Syria
Syria has denied reports of chemical weapons being used in Damascus.
BEIRUT - A Damascus opposition monitoring group said on Wednesday 494 people had been killed in a gas attack and shelling by President Bashar al-Assad's forces on Wednesday, citing data from medical centres in the Syrian capital.
The Damascus Media Office said in a statement 150 bodies were counted in Hammouriya, 100 in Kfar Batna, 67 in Saqba, 61 in Douma, 76 in Mouadamiya and 40 bodies were collected from Irbib.
"The attack began at around 3.00 am. Huge numbers of civilians were subjected to the gases. The numbers continued to increase rapidly as they suffocated to death, with lack of necessary medical supplies to save them," the statement said.
Earlier on Wednesday, the Syrian Observatory for Human Rights said dozens of people were killed, including children, in fierce bombardment. It said Mouadamiya, southwest of the capital, came under the heaviest attack since the start of the two-year conflict.
It called on the UN chemical experts and international organisations to visit the affected areas to ensure aid could be delivered and to "launch an investigation to determine who was responsible for the bombardment and hold them to account."
Syrian authorities and rebels have accused each other of using chemical agents in the course of the civil war, in which 100,000 people have been killed.
More than 100,000 people have died in Syria's civil war and millions have been displaced. Protesters took to the streets in March 2011 to call for democratic reforms but were fired on by security forces, leading to an armed uprising.