Syrian activists film UN monitors touring Homs
Anti-government activists say snipers in the central city of Homs shot dead two people on Sunday as monitors toured the city.
It comes as the UN's Syria mission chief arrived in Damascus and called for cooperation with Kofi Annan's peace plan.
Meanwhile activists' footage purporting to show UN monitors touring a devastated Homs neighbourhood on 28 April, has been posted online.
The BBC's Jim Muir reports from the Lebanese capital Beirut.