BEIRUT -- Activist groups said yesterday that about 5,000 people were killed in Syria's civil war in August, the highest monthly figure ever reported in nearly a year and a half of fighting as President Bashar Assad's regime unleashed crushing air power against the revolt for the first time.
UNICEF, the UN children's fund, put the death toll for last week alone at 1,600, the largest weekly figure to date.
"The past month witnessed large massacres, and the regime was conducting wide operations to try to crush the uprising," said Omar Idilbi, a Cairo-based activist with the Local Coordination Committees. "Last month's acts of violence were unprecedented."
The 17-month-old civil war saw a major turning point in August when Assad's forces began widely using air power for the first time to try to put down the revolt. The fighting also reached Syria's largest city, Aleppo, which had been relatively quiet for most of the uprising.
The Britain-based activist group Syrian Observatory for Human Rights said 5,440 people, including 4,114 civilians were killed in August. The LCC put the toll at 4,933 civilians.
The Observatory and the LCC said more than 100 people were killed on Sunday throughout Syria. The groups have been reporting 100 to 250 deaths a day over the past week.
The two main activist groups also released new death tolls for the entire uprising since March 2011. The Observatory said more than 26,000 have been killed, including more than 18,500 civilians. The LCC put the death toll at more than 23,000 civilians. The LCC does not count members of the military who are killed, but the Observatory does.
"The reason behind the high death toll is military operations, shelling, clashes and air raids," said Rami Abdul-Rahman who heads the Observatory.
Lakhdar Brahimi, the UN's new envoy to Syria, told Assad's regime on Saturday that change is both "urgent" and "necessary" and that it must meet the "legitimate" demands of the Syrian people.