Syrian activists say government forces clashed with rebels across the country Sunday, even as Damascus defended itself against widespread condemnation over a military operation last week that activists described as a massacre.

The opposition Syrian Observatory for Human Rights said at least 14 people were killed in clashes Sunday. On its Facebook page, the Britain-based group posted raw video footage that allegedly showed some of the clashes over the past few days in Aleppo and Idlib provinces.

The group also said government bombardments were continuing in the provinces of Hama, Homs, Aleppo, Dera'a and Deir Ezzor, as well as a Damascus neighborhood.

The videos and casualty figures have not been independently verified.

Meanwhile, Syria is denying that government forces used heavy weapons and aircraft against the village of Tremseh last Thursday.

A Syrian foreign ministry spokesman says the military operation in the village targeted armed fighters. He said 39 people were killed, and all but two of them armed.

Syrian activists said more than 200 people were killed during a massacre by government forces.

The spokeswoman for U.N. monitors in Syria, Sausan Ghosheh, said the government attacks in Tremseh appeared to target the homes of activists and army defectors. She said a wide range of weapons was used including artillery, mortars and small arms.