by Reuters

Rough Cut (no reporter narration)

STORY: After months of waiting, the United Nations is finally in Syria to investigate claims of chemical weapons use.

Swedish scientist Ake Sellstrom will lead the 20-member team in determining whether sarin and other toxic nerve agents were used. The team will not be trying to establish who used the weapons though.

The use of chemical weapons has long been an issue of contention in the international community.

Syria and its ally Russia have accused rebel groups of using sarin in multiple attacks in March while the U.S. has said that the government of President Bashar al-Assad used chemical weapons in June.