Syrian fighter jets have carried out a series of strikes against the Islamic State of Iraq and Levant (ISIL) group in and around the ancient city of Palmyra, according to a military source.

The source was quoted by the AFP news agency on Tuesday as saying that the Syrian air force struck more than 160 ISIL targets, while state television reported that at least 50 "terrorists" were killed in the assault.

ISIL captured the historical city on May 22 after a week of battling government forces and forcing them to retreat.

"The air force struck more than 160 Daesh [ISIL] targets, killing and wounding terrorists, and destroying weapons and vehicles equipped with machine guns" on Palmyra's outskirts and elsewhere in the east of Homs province, the military source said.

"Military operations, including air raids, are ongoing in the area around al-Suknah, Palmyra, the Arak and al-Hail gas fields and all the roads leading to Palmyra."

In a separate development on Tuesday, Syrian state television reported that at least 140 fighters had been killed in air force attacks on an ISIL fighters' base in Raqqa province.

Government criticised

Local activists in Palmyra have criticised what they call the Syrian government's "indiscriminate" air strikes, saying civilians are bearing the brunt of the attacks.

The Palmyra Media Centre, a monitoring group on the ground, released a statement on Monday evening condemning the deadly air raids, which they say destroyed numerous residential buildings.

"At least 15 people, including women and children, have been killed and dozens of others injured by the air raids," the group said.

It also accused the government of using ISIL's takeover as a "fabricated pretext to bombard the city and its people".

ISIL captures UNESCO World Heritage site of Palmyr
The group challenged the government's claim on Sunday that ISIL massacred 400 civilians.

Nasser, of the Palmyra Media Centre, told Al Jazeera that most of those killed were government troops captured by ISIL fighters after taking over the town on Wednesday.

"Shabiha [a term used to describe pro-regime militias and supporters], including men and women, were the ones targeted and killed," he said.

Also on Tuesday, an activist on the ground told Al Jazeera, Syrian government helicopters dropped at least six barrel bombs over the Damascus district of Yarmouk, wreaking havoc in residential areas and causing numerous casualties.

Trapped under rubble

Rami al-Sayed, the activist, said attempts were made to rescue civilians trapped under the rubble of buildings.

Another activist reported that one body had been recovered and at least three people had suffered injuries.

He said the bombings came amid a barrage of "various types of weapons, including mortar shells, and rockets".

Sayed said the surge in attacks coincides with ongoing attempts by Fatah al-Intifada and the General Command, two Palestinian groups which back the Syrian government, to enter the district and seize it from the Nusra Front and its loyalists.

Syrian activists posted video online that purportedly shows destruction caused by the barrel bombs in Yarmouk.

Additional reporting by Ryan Rifai in Doha

Activists said government helicopters dropped several barrel bombs over the Damascus district of Yarmouk [Ahmad/Al Jazeera]

Source: Al Jazeera and agencies