People stand in front of damaged buildings, in the town of Douma, the site of a suspected chemical weapons attack, near Damascus. Photo: AP

A UN security team was fired at on Tuesday while on a reconnaissance mission in the Syrian town of Douma ahead of the deployment of experts investigating an alleged chemical attack, a UN official said.

"Shots were fired yesterday at a UN security team doing a reconnaissance in Douma," the official told AFP. "They were not injured and returned to Damascus."