A string of government airstrikes on rebel-held areas of northern Syria have killed at least 44 people, activists said, as al-Qaeda-linked rebels captured one of the country’s oil field in the east.

Rami Abdurrahman, the director of the Britain-based Syrian Observatory for Human Rights, said the attack on the rebel-held town of al-Bab near the northern city of Aleppo is the deadliest of the three raids. He said that strike killed 22 people.

Fighter jets also bombed two rebel-held districts of Aleppo, Syria’s largest city. Government warplanes missed their target in the Halwaniyeh neighborhood and sent bombs into a crowded vegetable market, killing 15 people, Abdurrahman said. Seven people died in a third airstrike in the Karam el-Beik district, according to the activist group.

Syrian state television confirmed the fighter jets were in the north, but said they targeted “gatherings of terrorists” in Aleppo, killing a large number of them.

Another activist group, the Aleppo Media Network, confirmed yesterday’s airstrikes and posted a video of what it says was the aftermath of the al-Bab raid.

Meanwhile, fighters from al-Qaeda-linked Jabhat al-Nusra ousted government troops from the al-Omar field yesterday during an overnight battle, Abdurrahman said.

It is not clear if the field is operational. Before the uprising began in early 2011, the oil revenues provided around a quarter of the government’s budget.

In 2010, Syria produced about 380,000 barrels a day.

Oil exports have ground to nearly a standstill since. Syrian President Bashar Assad’s government now imports refined fuel supplies to keep up with demand amid shortages and rising prices.

In late 2012, rebels began seizing fields in Deir el-Zour, one of two main centres of oil production.

In February, they captured the large Jbeysa oil field after three days of fighting. A year ago, rebels briefly captured al-Omar field only to lose it to government troops days later.