Renewed violence in the Yemeni capital killed at least 15 people on Thursday as forces loyal to the regime and its opponents shelled each other's strategic positions from hills surrounding the city, medical and security official said.
The shelling over the city has terrified residents and emptied out city streets, already pockmarked by street battles between rival forces in different corners of the capital. A number of shops in a main boulevard in Sanaa were torched from earlier mortar shelling and oil spots covered the streets after electricity transformers also took a hit.
Smoke billowed from the opposite edges of the city, as two military officials said rival forces were caught in an exchange of artillery and mortar shelling from northern and southern hills at the edge of Sanaa. It was not clear what was hit by the shelling. The Republican Guards, forces loyal to Saleh and led by the son of President Ali Abdullah Saleh, have been in control of the south of Sanaa, while defecting military units led by Maj. Gen. Ali Mohsen al-Ahmar, a former Saleh aide who sided with the opposition, hold the city's north.
Officials said six people were killed in central Sanaa when government forces shelled thousands gathered for a protest there with mortars and rocket propelled grenades. Snipers on rooftops also targeted the protesters at Change Square, the center of Yemen's seven-month-old uprising, and adjacent streets.
Three bystanders were killed by a mortar shell in Sanaa's northern Hassaba district, the officials said. The district is home to several of the tribal chiefs who switched sides in March to join the opposition against Saleh's 33-year rule. The Interior Ministry later said four gunmen among supporters of Saleh were also killed. The rival side said one of its fighters was shot dead and 13 were wounded.
The house of a former defense minister, who has declared his support for the protesters, was also hit by government shells, leaving one of the guards dead, a defecting military official said. The former minister himself was unharmed.
The latest deaths took to about 100 the number of people killed in Sanaa and elsewhere in Yemen since Sunday, in the worst bout of bloodshed in months. The deaths also shattered hope that a cease-fire negotiated on Tuesday could be restored and significantly diminished the chances for a proposal by Yemen's Gulf Arab neighbors to end the crisis.
The Gulf plan, backed by the United States, provides for Saleh to step down in exchange for immunity from prosecution and for the vice president to assume power until elections.
Yemen's turmoil began in February as the unrest spreading throughout the Arab world set off largely peaceful protests in the deeply impoverished and unstable corner of the Arabian Peninsula that is also home to an al-Qaida offshoot blamed for several nearly successful attempted attacks in the United States.
Saleh's government responded with a heavy crackdown, with hundreds killed and thousands wounded so far.
The shelling over the city on Thursday also raised concern that the circle of fighting has widened to endanger thousands of civilians. The head of a human rights center in Sanaa said his office was badly damaged by the shelling Thursday. The same building houses the offices of Al-Jazeera TV, which were also damaged.
The officials who gave Thursday's casualty toll spoke on condition of anonymity because they were not authorized to talk to reporters. They said that scores of homes and stores across central Sanaa were damaged or caught fire as a result of random shelling blamed on government forces.
The shelling also ruptured many water tanks traditionally stored on rooftops of Yemeni homes, inundating the streets below. Sanaa has for weeks suffered from acute water and power shortages, forcing residents to rely on power generators and buy water drawn from wells and sold on a thriving black market.