The Syrian government and rebel forces had agreed to a break in the fighting beginning Friday, in observance of the four-day Eid al-Adha festival.
Thirty-three people were killed in and around Damascus, the Syrian network for human rights said. Five people were killed in the eastern city of Deir Ezzor, where the Syrian Observatory for Human Rights said three government troops were killed.
The Syrian government claimed terrorists targeted a church in Deir Ezzor. However, opposition forces said a military police building appeared to be the target.
The report said six people were killed in Daraa, six in Aleppo, five in Idlib and four in Hama.
Rebels claim 100 people were killed in clashes shortly after the cease-fire went into effect Friday, CNN reported.
Fidaa Itani, a Syrian journalist working for Lebanese television was detained briefly by Syrian opposition forces, The (Beirut) Daily Star reported.
A Lebanese television station Saturday quoted a rebel group as saying Itani had been detained "because his work was not suitable with the course of the Syrian revolution and revolutionaries."
The statement said the journalist had taken numerous pictures of buildings while accompanying a group of rebels and had been "placed under house arrest for a short period of time."