The Syrian Network for Human Rights said in a written statement the 113 fatalities included 16 child and 11 women. Half of the deaths occurred in Damascus and surrounding vicinity.
Opposition sources told China's official Xinhua News Agency the fighting around Damascus included airstrikes by Syrian MiG jets.
A four-day truce called for the Eid al-Adha appeared to have virtually collapsed by Sunday. The state-run Syrian Arab News Agency said rebels had violated the cease-fire for three consecutive days, but were not having much success against government forces.
Attacks were reported at various crossroads and checkpoints across Syria, as well as at two hospitals in Harasta. Government troops fended off each reported assault and in the process killed a rebel leader known as Abu Mussab.
Western news media are not allowed inside Syria, so the reports of fighting cannot be independently verified.