BEIRUT: Explosions were heard near Damascus International Airport in the early hours of Thursday, a monitoring group said, without specifying the cause.

"The blast was huge and could be heard in Damascus," said Rami Abdel Rahman, head of the Syrian Observatory for Human Rights.

Read more: Three dead in Israeli attack on Syria military camp

Earlier on April 23, an Israeli attack on a Syrian camp for pro-government forces killed three fighters near the Golan Heights on Sunday, an official from the forces said.

The official told AFP that two fighters were also wounded in the attack on the Al-Fawwar camp near Quneitra in southwestern Syria, adding that it was unclear whether the damage was inflicted by an air strike or shelling.

The Syrian Observatory for Human Rights monitoring group confirmed the early Sunday attack but had no further details.

Israel´s army on Friday said it targeted positions inside Syria in retaliation for mortar fire that hit the northern part of the Golan Heights.

Syria´s official news agency SANA said Israel had struck a Syrian army position in the province of Quneitra on the Golan plateau, "causing damage".

This is a developing story and will be updated as more information is received.