The chief of the global chemical-weapons watchdog says it remains unclear when a team of international experts can visit the Syrian town of Douma to investigate an alleged deadly chemical attack there.
The director-general of the Organization for the Prohibition of Chemical Weapons (OPCW), Ahmet Uzumcu, made the comment on April 18, after UN security experts came under fire in the town.
Western states have accused the Syrian government of an April 7 chemical attack in Douma, near Damascus, where the World Health Organization said 43 people who died suffered "symptoms consistent with exposure to highly toxic chemicals."
The United States, Britain, and France bombed several Syrian government sites on April 14 in retaliation.
Western powers also suggested that the government and its ally, Russia, may be delaying the OPCW visit to tamper with evidence.
Damascus and Moscow insist the April 7 incident was fabricated.
Uzumcu told a meeting of the organization on April 18 that the OPCW team, which arrived in Damascus over the weekend, will not visit Douma until the UN security experts deem it safe and only if the chemical-weapons inspectors "can have unhindered access to the sites."
"At present, we do not know when the team can be deployed to Douma," he added.
Uzumcu said that the UN security team was set to perform reconnaissance at two sites in Douma on April 17 ahead of the arrival of the OPCW inspectors.
When the security team arrived at the first site, a large crowd gathered and the UN experts decided to withdraw, he said. At the second site, "the team came under small-arms fire and an explosive was detonated."
There were no casualties and the team returned to the capital.
The OPCW chief said the two suspected attack sites were under the control of the Russian military police.
In Washington, U.S. Defense Secretary Jim Mattis blamed Syria's government for delays in inspectors reaching the sites, saying it had a history of trying to "clean up the evidence before the investigation team gets in."
"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 and seal what they have done using chemical weapons," Mattis said.