At least 3,500 people have now been killed in Syria since protests against the government began in mid-March, according to new UN figures.
A spokeswoman for the UN High Commissioner for Human Rights said the total was a conservative figure based on "credible sources on the ground" although the agency itself has no one posted in the country.
The figure includes 19 killed on Sunday during the Muslim holiday of Eid al-Adha, also known as the Festival of Sacrifice.
The government of president Bashar Assad has largely sealed off the country from foreign journalists and prevented independent reporting, but amateur videos posted online and details gathered by activist groups have been filtering out.
Meanwhile activists say fresh attacks by Syrian troops have killed two people in the central Syrian city of Homs as the military struggles to consolidate control over the district.
Homs-based Salim al-Homsi said a man and a woman were killed by security forces' fire in the neighbourhood of Baba Amr.
Troops the day before had stormed the southern and western parts of the district, a stronghold for anti-government military defectors who have resisted the week-long government offensive in Homs.
Syrian troops have control of large sections of the district but are still conducting raids and operations in other areas.