Medical and security officials in Yemen say pro-regime forces -- including snipers firing from rooftops -- have killed at least 20 more protesters in the capital.
Heavy gunfire and shelling could be heard in Sanaa after protesters tried to seize parts of the city where security forces on September 18 had fired into a massive crowd of demonstrators, killing at least 26 and injuring hundreds.
Correspondents say plainclothes security forces were firing their weapons this morning near so-called Change Square. The demonstrators want the ouster of President Ali Abdullah Saleh and his close circle, who have ruled the impoverished Arab peninsula country for 33 years.
Reports say snipers were firing from rooftops at demonstrators on Sanaa's central Hayel Street and near Sanaa University.
Demonstrators said they were trying to extend the size of a protest camp they have erected at Change Square and set up more tents for a crowd of demonstrators that has been growing in size. The demonstrators -- undeterred by the violence in Sanaa -- also are calling for their mass demonstrations to continue today.
Late on September 18, at least 26 people were killed and hundreds were injured when Saleh's troops fired live ammunition into a crowd numbering in the tens of thousands. Reports suggest the death toll from the incident could rise. Human rights activists say at least 450 people have been killed during government crackdowns against protesters since February.
A wounded Yemeni protester is rushed to hospital by comrades on a motorcycle following clashes with government troops on September 18.
Tom Finn, a British freelance journalist in Yemen, says the killings by Saleh's security forces were "essentially a massacre."
Finn says the demonstration on September 18 was the largest and angriest crowd that he has seen during the eight-month uprising against Saleh's rule. Finn also says the killings near Change Square have left protesters in Sanaa angrier and more determined than ever to continue their rallies until Saleh's regime collapses.
Government officials today are rejecting accusations that the regime had planned the September 18 attack, claiming the protesters were shot at because they tried to destroy an electricity plant.
Yemen's state-controlled television also is downplaying the shootings, reporting that the violence was necessary because demonstrators had charged at government troops and that most of the injured were soldiers.
Fired Live Ammunition
State-controlled television also claims that video footage uploaded to the Internet showing dead and injured protesters was not footage from Sanaa.
But those claims are contradicted by a vast amount of amateur video footage and a large number of firsthand witness accounts -- including reports by independent foreign journalists -- confirming that government troops fired live ammunition at a mass demonstration.
According to one local resident, a supporter of Saleh who escaped from the conflict, the demonstration began peacefully but deteriorated into violence later.
"The protesters spilled onto the Change Square. At first it was a peaceful demonstration, but later the trouble began when they took guns, threw petrol bombs at cars, and three or four cars [were] still on fire, and they hit people with slingshots," the witness said. "Now many injured people are trying to escape from the clashes."
Many other witnesses say government security forces used heavy machine guns, mortar shells, and even rocket-propelled grenades in the clashes, the first direct conflict between demonstrators and government forces and the deadliest in Yemen for several months.
Opposition leaders overnight were calling for doctors to come to the aid of injured demonstrators who were lying in pools of their own blood while Saleh's security forces blocked ambulances from taking them to hospitals.
Soldiers who have defected from Yemen's military to support the protesters are calling on other troops to join them in putting "the remnants of the Saleh regime on trial," saying continued support for Saleh's regime is "a crime."
Both government forces and the opposition have strengthened security in areas under their control today. Government troops have set up many checkpoints and were checking all motor vehicles passing through.
Opposition supporters say they have set up checkpoints around their headquarters in Sanaa.
"All the urban areas and border areas of Sanaa are now under the control of Saleh's forces," one demonstrator said. "They attacked local residents and our supporters."
Meanwhile, living conditions in Sanaa continue to deteriorate as the impact of the ongoing protests hits Yemen's economy.
The British-based international charity Oxfam says fuel prices have risen more than 500 percent since protests against President Saleh began in January. It says the protests have "triggered rapid inflation, damaged livelihoods and industry," and caused food shortages that have raised food prices beyond what most people can afford.
Oxfam says one in three Yemenis is going hungry each day because months of political stalemate have brought the economy to the verge of collapse and pushed the government toward "total paralysis."
Oxfam says "widespread hunger and chronic malnutrition" have taken hold in the country of 22 million people. It is warning of an impending "calamity" if the international community does not immediately increase relief efforts for Yemen.
Saleh has been recovering in Saudi Arabia from wounds suffered during an attack by tribal fighters on the presidential compound in June. His government has characterized that attack as an attempted assassination.
Saleh has refused to step down from power, despite regional and international demands for him to do so. Last week, Western diplomats said they thought Saleh was not planning to return to Yemen. They said Saleh was expected, instead, to transfer powers to his vice president within 10 days.
compiled from agency reports