Almost half of those killed in Syria since the outbreak of the anti-regime revolt in March 2011 have died since a failed UN-Arab League truce was due to come into force, a monitoring group said on Sunday.
"Some 45 percent of those killed in Syria have been killed since April 12," said Rami Abdel Rahman, director of the Britain-based Syrian Observatory for Human Rights.
Abdel Rahman said 9,098 people have been killed since the ceasefire brokered by international envoy Kofi Annan was supposed to begin.
"This month alone, 3,867 people have been killed -- 2,764 civilians, 1,000 regime troops and 103 defectors," he added, noting that he counted civilians who have taken up arms against the regime under the civilian category.
"It's just getting more and more violent," he said.
More than 20,000 people have been killed since the uprising broke out in mid-March last year, according to the watchdog's figures.
It is not possible to check casualty tolls independently in Syria. The United Nations has a troubled military observer mission in the country but has stopped giving figures for the overall estimated death toll.