At least six people were killed and over 50 others wounded Saturday as a result of the rebels' shelling against a district in Syria's northern city of Aleppo, according to Syria's national TV.

The TV said the death toll does not include the body parts that were found in the scene, as a result of the heavy shelling by the extremist groups on the government-controlled Sulaimanyeh district in Aleppo.

Many buildings in this district were completely destroyed and tens of civilians are stuck under the rubble, the TV added.

The TV also aired footage of the targeted site, showing huge destruction that has befallen buildings and streets.

Meanwhile, a source in the city told Xinhua over the phone that the rebels in the eastern part of Aleppo fired tens of improvised rockets on the Sulaimanyeh, Hamidyeh and Alteliphone al-Hawai districts.

The rebels in Aleppo have repeatedly fired different kinds of rockets into the government controlled areas of that key province, near Turkey.

The government troops often drop crude barrel bombs on the rebel-held parts of Aleppo, according to activists.

Separately, at least 24 militants with the Islamic State (IS) group were killed over the past 24 hours during clashes with the Kurdish fighters of the People's Protection Units (YPG) and allied fighters in the vicinity of the predominately-Assyrian village of Tal Tamer in northeastern Syria, said the Syrian Observatory for Human Rights.

It said the YPG are advancing in the countryside of Tal Tamer, which had recently been overrun by the IS militants.

Also on Saturday, at least 20 Syrian soldiers were killed when repelling an attack by extremist groups against a military airbase in Syria's southern province of Sweida, according to the Syrian Observatory for Human Rights.

Among the killed soldiers, 12 were with the Palestinian Liberation Army (PLA), a brigade in the Syrian army that comprises of Palestinian refugees in Syria, it said.

It said militants, believed to have been with the Islamic State (IS) group, launched an offensive against the Khalkhala airbase in the countryside of Sweida Friday, adding that 15 of the assailants were also been killed during the offensive.

Other activists said the Syrian forces managed to repel the attack against the airbase in Sweida, a predominantly Druze province that has largely remained safe during Syria's four-year-old conflict.