Non-state armed groups were reportedly responsible for the remaining deaths.
Bachelet also reported that 51 medical facilities had been damaged in the fighting.
"I should not need to emphasize that these figures are appalling, shameful and deeply tragic," Bachelet said.
"In a bid to take control of territories, there appears to be little concern about taking civilian lives," she added, urging the battling sides and other influential powers to stop the bloodshed.
On April 30, the Syrian government, supported by Russian air power, began a military offensive against rebels in the provinces of Hama and Idlib, forcing thousands of people to flee.
A ceasefire in the region collapsed in August.
Since then, the government forces have regained dozens regions in the southern countryside of Idlib and the northern rural areas of Hama which were under the control of rebels.
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