Government troops shelled residential areas in central Syria on Sunday, May 27, activists said, two days after the bombardment of a string of villages in the same region killed more than 90, many of them children, according to the Associated Press.

Friday's assault on Houla, an area northwest of the central city of Homs, was one of the bloodiest single events in Syria's 15-month-old uprising. The UN said 32 of the dead were under the age of 10.

The attacks sparked outrage from American and other international leaders, and renewed concerns about the relevance of a month-old international peace plan that has not stopped almost daily violence.

Sunday's shelling hit neighborhoods in the central city of Hama and the rebel-held town of Rastan north of Homs, the Local Coordination Committees and the Britain-based Syrian Observatory for Human Rights said.

The two groups also reported clashes between troops and rebels in Hama, in the Damascus suburb of Harasta and in the capital's central Midan district. They said a bomb struck a security vehicle in the capital's upscale district of Mazzeh - near a military airport, according to the LCC.

The Observatory said the vehicle bombing caused casualties but did not have other details on the dead or wounded from the day's violence.

A video posted online by activists showed thick black smoke billowing from what it said was Mazzeh.