UNITED NATIONS • A security team from the UN was fired at while on a reconnaissance mission in the Syrian town of Douma to prepare for the deployment of experts investigating an alleged chemical attack, officials said.

"Shots were fired (on Tuesday) at a UN security team doing a reconnaissance in Douma," a United Nations official told AFP yesterday. "They were not injured and returned to Damascus."

Experts from the Organisation for the Prohibition of Chemical Weapons (OPCW) chemical watchdog are in Syria to investigate the April 7 incident in which Western countries and rescue workers say scores of civilians in Douma were gassed to death by government forces, allegations which Damascus denies.

The experts had been waiting for the green light from the UN security team before beginning their on-site investigation of the alleged April 7 attack. Syria and its backer Russia deny using poison gas, hindering the investigation or tampering with evidence.

British ambassador Peter Wilson told reporters in The Hague that the security team on Tuesday travelled to two sites in Douma, escorted by Russian security police.

The officials were greeted by a "large crowd" of protesters at one site, forcing them to withdraw while at the second site, "they were subject to small-arms fire and an explosion", Mr Wilson said, citing information from the director-general of the OPCW.

Mr Ahmet Uzumcu, the head of the OPCW, told ambassadors in The Hague that it was unclear when the fact-finding mission would be able to deploy to Douma, Mr Wilson added.

The UN official, who declined to be named, said the security team would stay in Damascus with the OPCW experts for the time being.

Douma had been the last rebel stronghold near the capital before it was recaptured during the April 7 offensive. The inspectors arrived in Damascus last Saturday, when Britain, France and the United States launched military strikes against what they said were targets linked to Syria's chemical weapons programme. The strikes were the first coordinated Western action against President Bashar al-Assad in seven years of war.

The US-led intervention has threatened to escalate confrontation between the West and Mr Assad's ally Russia, although it has had no impact on the fighting on the ground.

A delay in the arrival of the inspectors at the Douma site has become a source of diplomatic dispute, because Western countries accuse Damascus and Moscow of hindering the mission. The US and France have both said they believe the delay could be used to destroy evidence of the poison attack.

One source told Reuters the advance team had "encountered a security issue" during the visit to Douma, including gunfire which led to the delay. Another said the advance team had left after being met by protesters who demanded aid and hearing gunfire.

Syria's UN ambassador Bashar Jaafari told the Security Council on Tuesday that the OPCW experts would begin their investigation once they received the all-clear from the security team.

"If this United Nations security team decides that the situation is sound in Douma, then the fact-finding mission will begin its work in Douma tomorrow," Mr Jaafari said. He stressed that the "Syrian government did all that it can do to facilitate the work of this mission" but that it was up to the UN and the OPCW to decide whether to deploy.

AGENCE FRANCE-PRESSE, REUTERS