At least five people were killed on Sunday in a rocket attack by the rebels on two districts in the central city of Homs, according to the state-run SANA news agency.
Four civilians were killed and some others were injured as " terrorists" fired rocket shells on Karm al-Shami, and another civilian was killed in a similar attack in al-Zahra district, the report said.
In the capital Damascus, rebels fired a mortar shell at the Red Crescent Hospital in Baghdad street, causing material damage but no human casualties.
Separately, SANA said as many as 350 wanted suspects related to recent attacks turned themselves in to authorities in Madaya in Damascus countryside on Sunday, quoting a source at Damascus Police Command.
The Syrian troops have been fighting rebels for almost three years. The international community is preparing for the holding of the Geneva II peace conference designed to seek a political solution to the nation's protracted crisis.
Despite their incessant mortar attacks, the rebels have been losing momentum recently due to the escalating infighting between the self-labeled "moderate" and the Islamic State of Iraq and the Levant (ISIL).
Several rebel battalions have recently turned against the powerful ISIL, which recently declared the establishment of an Islamic emirate in Iraq' s Fallujah province.
Meanwhile, the Britain-based Syrian Observatory for Human Rights said Sunday that a Libyan suicide bomber detonated himself at a rebel battalion in the Masaken Hanano neighborhood in the northern province of Aleppo, killing some rebels.
Another suicide bomber, the Observatory said, detonated a car bomb at a rebel checkpoint in the same neighborhood, killing at least two rebels.
The Observatory said that the infighting between the rebel groups in Syria have killed at least 500 people since the start of last week.