Amateur video has emerged, purporting to show a UN team in the Syrian city of Homs when gunfire rings out through the streets.
The mission members are in the country to monitor a fragile ceasefire.
Residents are seen in the footage helping the team to safety. It was the first time the monitors had been allowed to visit the opposition stronghold.
There have been continuing reports of violations since the ceasefire was introduced earlier this month.
Meanwhile, the UN Security Council has voted unanimously to deploy up to 300 unarmed military observers to Syria for three months.
But the deployment will only start if UN chief Ban Ki-moon feels conditions on the ground are suitable.