At least 74 soldiers and pro-regime fighters were killed in the attacks by the Daesh on their camps in Hama city, central Syria, the Syrian Observatory for Human Rights (SOHR) reported on Sunday.
Fighting has been going on since Friday in Sheikh Helal area on the eastern outskirts of Hama as ISIL fighters try to cut the supply lines of the regular troops between Hama and the northern city of Aleppo.
SOHR said it documented 74 deaths among the regular troops, noting that the death toll could rise further since a number soldiers are reported missing.
Meanwhile, Al-Nusra Front and other Islamist groups launched mortar attacks on the northern city of Idlib, killing five civilians and wounding 16 others, some seriously.
A mortar round, fired by the regular troops, resulted in a yet-to-be-specified number of casualties in Me'rata village, Jabal Al-Zawia district, in Idlib.
In Deir Sonbol neighborhood in the same district a military helicopter crashed and the opposition forces captured its six-member crew and later killed one of them.
The state-run TV said the plane crashed while trying to make an emergency landing due to a technical failure.
The regime launched several air raids on the area after the accident.
In Inkhil town in the southern Daraa governorate a missile attack killed seven people while the Air Force dropped barrel bombs on Basra Al-Sham town, killing at least nine people including an Islamist militant leader.
In a related development the Islamist Ahrar Al-Sham (the Free Men of the Levant) and Alwiyat soqour Al-Sham (the Levant's hawks brigades) announced merger under the name of the Islamic movement of Ahrar Al-Sham.
The new movement reaffirmed resolve to topple the regime of President Bashar Al-Assad as the Syrian revolutions enters its fifth year.