In this image made from video and accessed, a Syrian rebel fires his weapon at Syrian Army positions during fighting in Aleppo.

Beirut -

August marked the bloodiest month in Syria since the uprising against President Bashar al-Assad's regime erupted in March last year, with at least 5 440 people killed, a watchdog said on Sunday.

Last week alone accounted for 1 248 deaths, according to figures compiled by the Syrian Observatory for Human Rights, which has a network of activists on the ground in Syria.

The Britain-based watchdog said the August figure comprised 4 114 civilians, 105 rebel fighters and 1 221 regime troops. The group includes in its civilian toll those who have taken up arms against Assad's forces.

According to the Observatory, at least 26 283 people have been killed in Syria since the revolt began in March last year - 18 695 civilians, 1 079 defectors and 6 509 troops.

The toll does not account for thousands of people missing in Syria's jails, Rami Abdel Rahman, the Observatory's director told AFP.

Due to restrictions on the media in Syria, the figures are impossible to verify. - Sapa-AFP