World Bulletin / News Desk

U.N. chemical weapons inspectors investigating allegations of chemical and biological weapons use during Syria's civil war left Damascus on Monday after their second mission in two months, witnesses said.

A convoy of four United Nations vehicles carrying the team departed from a central Damascus hotel around 1.30 p.m. (1030 GMT), and was expected to arrive in Beirut later in the day.

Another team of U.N. experts, tasked with starting the process of verifying and eliminating Syria's chemical weapons, is expected to arrive in Syria this week.

Their mission, endorsed by the U.N. Security Council last week, was hammered out by Washington and Moscow after an Aug. 21 chemical weapons attack in Damascus prompted threats of Western air strikes on Syria.

Inspectors who were in the country at the time confirmed that sarin gas was used in the attack, which killed hundreds of people.

President Bashar al-Assad's Western opponents said the inspectors' report left little doubt that his forces were to blame for the attack.

Syrian authorities denied the accusation, and Russia has said the inspectors' report did not provide irrefutable proof that Assad's forces were responsible.

"We have presented the evidence we possess ... that lead to the conclusion that this was done by the opposition. And we have serious suspicions that such attempts continue," Russia's Foreign MinisterSergei Lavrov told Kommersant newspaper.

The inspectors who left Damascus on Monday investigated six other alleged cases of chemical weapons use, including three reported around Damascus in the days following the Aug. 21 attack.

Restrictions on media access made it difficult to follow the inspectors' activity inside Syria, but theUnited Nations said they would issue a comprehensive report on their findings next month.