In the suburbs of Deraa in Syria where protests flared last month it is being reported that forces loyal to the government have opened fire in areas of the city.
Campaigners claim eight tanks went into the old quarter with the army shooting at random. Several bodies were seen lying near a mosque.
It is a pattern being repeated in other cities across the country, according to reports from protesters. In Douma it is claimed scores of people have been arrested and all communications cut off.
At least 100 people are reported to have been killed since the start of the weekend, as protests continued despite President Bashar al-Assad ending the 48-year state of emergency in the country.
The campaign group Human Rights Watch called for a UN inquiry and international sanctions against Syria following the killings.
In Nawa, at a funeral for protesters killed by security forces, thousands gathered to call for the overthrow of the president. Witnesses say four people were shot dead.
Syrian writers have issued a declaration denouncing the crackdown in what analysts say is a sign of the outrage amongst the intellectual elite over the violence.
And according to security officials in neighbouring Jordan, Syria has closed all land borders with the country.