The violence, which also saw 25 soldiers killed, marks one of the bloodiest days of the revolt against President Bashar al-Assad's regime since it erupted in March.
Included in the 96 people killed were 10 dissident soldiers and six members of the security services, the Britain-based monitoring group said on Tuesday, without giving further details.
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The watchdog said in a statement received in Nicosia that 40 civilians were killed in Homs, nine in Syria's southern Daraa region where the revolt began more than 10 months ago, five in outlying districts of Damascus and one in northwestern Idlib region.
In addition, the bodies of a family of six killed last Thursday were found in the Karm al-Zeitun neighbourhood of Homs, it said.
On Sunday, 80 people were reportedly killed, equally divided between military and civilian deaths, in the most intense clashes of the uprising began, the Observatory reported.
