SANAA (AFP) - Gunmen killed three protesters tearing up posters of President Ali Abdullah Saleh on Thursday, raising to 19 the death toll in 24 hours and prompting Washington to say the time has come for a transfer of power. Pro-Saleh gunmen on the roof of the ruling party's headquarters in Al-Bayda, 210 kilometres (130 miles) southeast of Sanaa, opened fire at demonstrators tearing up posters of Saleh, witnesses and protest organisers said. Seven protesters were also wounded. In central Taez, Yemen's second largest city, central security forces and units from the Republican Guard opened fire to disperse the latest protest in Jamal Street. Dozens of protesters were wounded, said a medic at a field hospital in Freedom Square, the focal point of protests in Taez. Thursday's crackdown came after a day of heavy bloodshed during protests. In Sanaa, 12 people were killed and 340 wounded on Wednesday as security forces and plainclothes gunmen fired at protesters marching from University Square towards the government headquarters, medics and witnesses said. Elsewhere, police shot dead two protesters in Taez, and two others in the town of Dhamar and the city of Hudayda. "People want to march to the palace" of President Saleh, the protesters chanted, in an apparent escalation of their 15-week push to oust him. The interior ministry said protesters had attempted to break security cordons to "storm the radio (building) and government headquarters." It added that opposition gunmen positioned in a nearby building opened fire, resulting in the death of one protester and the wounding of others, the official Saba news agency reported. Besides gunfire and tear gas, security forces also used hot water on protesters at University Square, scalding at least 12 of them, a medic said. Tension was mounting ahead of Friday rallies arranged by both sides as they have done on the Muslim weekly day of prayers since the start of the unrest in late January.