Air strikes launched by the Syrian government have killed several civilians and injured dozens in the northern city of Aleppo as the ceasefire between the government and opposition groups crumbles.

At least 20 people were killed across Aleppo and several dozen injured in the attacks, according to sources on the ground.

The strikes targeted four different, predominantly civilian areas in the city, said Zouhir Al Shimale, a local journalist.

"These are all civilian areas, and people were near or at the mosques when the strikes hit," he told Al Jazeera by telephone, estimating that at least 30 civilians were injured in the Bustan al-Qasr area alone.

"The bombardment happened during the Friday prayers. I was on the way prayers when it happened in the al-Mashhad [neighbourhood]. People started going out of the mosque and running."

READ MORE: Death and destruction as Syria ceasefire buckles

Shimale said Aleppo's streets mostly emptied following the attacks, with people rushing home to avoid being in open spaces.

"People have gotten used to it. They know that at any moment, the regime could strike again."

According to the UK-based Syrian Observatory for Human Rights, government air strikes also targeted towns across Syria's Idlib province, killing at least three civilians.

Elsewhere in Syria, the Islamic State of Iraq and the Levant (ISIL, also known as ISIS) group claimed to have downed a plane of the government forces in the countryside of Damascus and captured its pilot.

However, citing a Syrian military source, Russian news agency Interfax said the plane, a Mig-23, belonged to the Syrian Air Force and crashed because of a technical fault.

"The plane had recently undergone repairs ... there was no attack from the ground. It crashed because of a technical fault. The pilot ejected," Interfax quoted the source as saying.



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The Syrian conflict started as a largely unarmed uprising against Syrian President Bashar al-Assad in March 2011, but has since morphed into a full-on civil war that has claimed the lives of more than 260,000 people, according to the UN statistics.

The opposition cited the dire humanitarian situation and the Syrian army offensive when it walked out of peace talks in Geneva this week, saying it needed a "pause". The future of Assad also proved a major sticking point.

The already shaky ceasefire between the government and some rebels was severely strained on Tuesday when at least 44 people were killed in air strikes on two markets in the northwest.

The Geneva talks are aimed at ending the five-year war by fashioning a political transition, writing a new constitution, and holding fresh elections by September 2017.