Police and snipers in civilian clothes have reportedly opened fire on anti-government protesters in Yemen.
According to medical sources, at least 15 people have been killed with hundreds more wounded as demonstrators in Taiz tried to storm the provincial government building. There were similar scenes in the Red Sea port of Hudaida as security forces used teargas on opposition forces.
President Ali Abdullah Saleh has said he will not stand for re-election in 2013 and has dismissed the idea of his son succeeding. He has also offered a referendum on a new constitution but many of the thousands camped around Sanaa University say he must go now.
The United States has reportedly given Saleh an ultimatum to leave office peacefully or face public calls for him to step down.