Syria's main opposition group on Tuesday denounced the killings during the Muslim fasting month of Ramadan, calling for an end to the "massacres" committed by President Bashar al-Assad's forces.
"More than 200 people died in 20 massacres committed in July," said Louay Safi, a member of the Syrian National Coalition.
"The number of deaths in total is approaching 2,000 throughout the month," he added.
He called for an end to the fighting during Ramadan, which is due to finish Wednesday or Thursday.
"The main dictator is Bashar al-Assad who sent the army to kill civilians," Safi said.
On Sunday, Assad reaffirmed his determination to crush the rebellion with an "iron fist," in a rare speech on Syrian state television.
He also dismissed the political opposition to his regime as a "failure" that could play no role in solving the country's brutal war.
The Syrian opposition has reiterated its offer of full cooperation with the UN investigation into the war crimes committed in the conflict, and soon will send their report to the UN Committee on Human Rights.
More than 100,000 people have been killed in Syria's war, according to the United Nations. Millions more have been forced by violence to flee their homes.