BEIRUT (AP) - President Bashar Assad's forces pressed on with a military offensive in eastern Damascus on Thursday, bombing rebel-held suburbs where the opposition said a chemical weapons attack the day before killed over 100 people.

The government has denied allegations it used chemical weapons in artillery barrages on the area known as eastern Ghouta on Wednesday as "absolutely baseless." The United States, Britain and France have demanded that a team of U.N. experts already in Syria be granted immediate access to investigate the site.

Syrian opposition figures and activists have reported widely varying death tolls from Wednesday's attack, from 136 to as high as 1,300. But even the most conservative tally would make it the deadliest alleged chemical attack in Syria's civil war.

The Britain-based Syrian Observatory for Human Rights said it had no word on casualties in the Thursday morning bombing of eastern Ghouta. It said Syrian warplanes conducted several air raids on eastern and western suburbs of Damascus, including three that took place within five minutes.

Wednesday's alleged chemical weapons attack left scores of children dead, their lifeless bodies appearing in amateur videos wrapped in white cloths, their pale skin unmarked by any wounds.