Members of a U.N. security team came under small-arms fire and an explosive was detonated as they tried to carry out a reconnaissance mission to a Syrian town awaiting chemical weapons inspectors.
"On arrival at Site 1, a large crowd gathered and the advice provided by the UNDSS [U.N. Department of Safety and Security] was that the reconnaissance team should withdraw," the head of the Organization for the Prohibition of Chemical Weapons (OPCW), Ahmet Uzumcu, said Wednesday. "At Site 2, the team came under small-arms fire and an explosive was detonated."
He said the incident occurred Tuesday, and the reconnaissance team returned to Damascus.
A U.N. source told VOA that none of the U.N. security team members were injured during the incident.
"At present, we do not know when the FFM team can be deployed to Douma," the OPCW chief added, referring to his organization's fact-finding mission.
A boy stands next to the remains of a missile, in Douma, near Damascus, Syria, April 16, 2018.
On Tuesday, there had been conflicting reports about whether the OPCW experts had arrived in Douma. The team wants to visit the site of the April 7 alleged chemical weapons attack that killed at least 40 people.
U.S. Defense Secretary Jim Mattis said Wednesday the delays raised the risk of evidence tampering.
"We are very much aware of the delay that the regime imposed on that delegation. But we are also very much aware of how they have operated in the past," he said. "In other words, using the pause after a strike like that to try to clean up the evidence before the investigation team gets in."
The United States and its allies blame the government of Syrian President Bashar al-Assad, while Russia and Syria insist no chemical attack took place.
The inspectors arrived Saturday in Syria, the same day the United States, Britain and France launched a barrage of missiles targeting three chemical weapons facilities in Syria.
Ken Ward, the U.S. ambassador to the OPCW, claimed Monday the Russians had already visited the site and "may have tampered with it," a charge Moscow rejected.
On April 9, Moscow's U.N. ambassador told the U.N. Security Council that Russian experts had visited the site, collected soil samples, interviewed witnesses and medical personnel, and determined no chemical weapons attack had taken place.
U.S. military officials have said the strikes were designed to send a powerful message to Syria and its backers, showing that the United States, Britain and France could slice through the nation's air defense systems at will.
"We did what we believe was right under international law," U.S. Defense Secretary Jim Mattis said Tuesday at the Pentagon. "I hope that this time the Assad regime got the message."
VOA's Jeff Seldin contributed to this report.