Assad gunment shot dead 13 civilians on Monday and Tuesday in the central Syrian protest city of Homs, rights activists say.
"Thirteen civilians were killed on Monday and Tuesday in several parts of Homs when the army opened fire as it carried out an operation in the city," rights activist Rami Abdel Rahman told reporters from Nicosia.
Late Monday another activist told reporters security forces swept into the flashpoint city and shot dead one civilian and wounding four others.
The wounded were taken to the Al-Bir Hospital, said Rihawi, who heads the Syrian League for the Defence of Human Rights.
Fierce fighting rocked Homs on Sunday, with activists reporting that more than 30 people were killed in skirmishes between Christians, Sunni Muslims and Alawites from President Bashar Al Assad's minority community.
The death toll in Homs has risen to at least 43 since Sunday.
Activists have said the violence in Homs could spark a new and dangerous turning point in more than four months of pro-democracy protests, with Rihawi telling reporters the sectarian in-fighting as a "dangerous signal of the break-up of Syrian society."
Abdel Rahman said the fighting in Homs erupted after three regime supporters kidnapped last week were killed and their dismembered bodies returned to their relatives.
"These clashes are a dangerous development that undermines the revolution and serves the interests of its enemies who want it to turn into a civil war," he said.
Activists say the Syrian government's crackdown on pro-democracy and anti-regime protests has left more than 1,400 civilians dead. Thousands more have been jailed.