At least seven people were killed in violence across Syria on Friday, including two children and a woman, the Syrian Observatory for Human Rights said.

Regime forces killed a child and arrested her family members during raids in the town of Jasem in southern Daraa province, the Britain-based watchdog said, adding that several homes in the town were torched.

Also in Daraa, snipers killed a young girl in the village of Giza, according to local residents.

In the central city of Hama, a child was killed by heavy artillery fire by regime forces and a woman was killed in her home by gunfire.

Two civilians were killed by regime forces in the Al-Tadamon district of the Syrian capital, the Observatory reported.

Elsewhere in Damascus province, heavy gunfire was reported near the town of Harasta, while the army suffered casualties in an attack on a military checkpoint at the town of Dariya.

The watchdog also reported an officer killed by an explosion in the northern city of Aleppo on Friday morning.

Regime forces fired on protesters who took to the streets of Aleppo, wounding several people at the biggest rally seen in Syria's second city since a revolt erupted last year, a watchdog said.

Besides Aleppo, protests demanding the ouster of President Bashar al-Assad also took place in Damascus, Deir Ezzor in the east, northeastern Hasaka, central Homs and Hama, and northwestern Idlib, according to the Observatory.

Violence persisted elsewhere, with regime forces renewing their bombardment of Rastan in central Homs province on Friday, according to the Observatory -- only a day after a blistering assault on the rebel stronghold.

Repression persists in Syria despite a truce officially established on April 12 and the presence of almost 260 military observers to monitor it.

More than 12,000 people, the majority of them civilians, have died since the Syrian uprising began, according to the Observatory, including more than 900 killed since the putative truce came into effect.