A London-based organization opposed to the rule of Syrian President Bashar al-Assad says at least 105 people were killed in Syria on Monday just a day before a UN peace plan is set to take effect.

The Syrian Observatory for Human Rights said on Monday that among the dead are 23 government security forces and eight rebels.

The group said at least 35 civilians, including women and children, were killed when government forces bombed a city in the province of Hama.

The group added that a clash between government forces’ helicopters and rebels as well as bombings in regions nearby Hama claimed the lives of 27 civilians.

Meanwhile, UN Secretary-General Ban Ki-moon strongly denounced Monday’s “fatal cross-border shootings from Syria into Turkey, as well as into Lebanon.” Ban also condemned Syrian security forces for shooting and killing a Lebanese TV cameraman while he was working in a Lebanese town near the Syrian border.