AMMAN: Jordan said on Thursday its warplanes had launched new strikes against the Islamic State group, after vowing a harsh response to the burning alive of one of its fighter pilots captured in Syria.

The announcement came as King Abdullah II personally paid his condolences to the airman's family, which has urged the government to “destroy” the jihadists, reflecting deep anger among Jordanians over the brutal murder.

“The Jordanian air force launched raids against positions of the Islamic State group,” said a government official, who did not want to be named.

He did not disclose where or when the strikes took place, saying the military would release a statement later.

Jordan has conducted regular raids against IS in Syria as part of a US-led campaign against the extremist group, which has seized swathes of the war-torn country and of neighbouring Iraq.

More than 200,000 people have died since anti-government protests broke out in Syria in early 2011, escalating into a multi-sided civil war that brought jihadists streaming into the country.

At least 57 people, including 12 children, were killed Thursday in a barrage of regime air strikes and shelling on rebel areas around the capital, according to the Syrian Observatory for Human Rights.

The assault on the Eastern Ghouta region came after rebels fired more than 100 rockets at Damascus, killing 10 people including a child, the Britain-based monitoring group said.

Harrowing video footage

The gruesome murder of airman Maaz al-Kassasbeh, who was captured by IS in December when his F-16 fighter plane went down in Syria, has increased support in Jordan for stepped-up military action against the jihadists.

“Jordan will wage all-out war to protect our principles and values,” the Al-Rai government newspaper wrote in an editorial.

"We are on the lookout for this band of criminals."

Abdullah cut short a visit to the United States and flew back to Amman on Wednesday after the harrowing video emerged of Kassasbeh's killing.

“The blood of martyr Maaz al-Kassasbeh will not be in vain and the response of Jordan and its army after what happened to our dear son will be severe,” he said afterwards.

On Wednesday, in response to the killing of the pilot, Jordan executed two Iraqis on death row -- female would-be suicide bomber Sajida al-Rishawi and Al-Qaeda operative Ziad al-Karboli.

Abdullah travelled to Kassasbeh's home town of Karak, 120 kilometres (74 miles) south of the capital, on Thursday where a traditional mourning tent was set up for the family to receive guests.

Hundreds of people, including representatives of the military and civilians, gathered as the king, wearing a red and white checked keffiyeh, sat next to the 26-year-old first lieutenant's father, Safi.

The airman's killing sparked outrage in Jordan and demonstrations in Amman and Karak, also the bastion of Kassasbeh's influential tribe.

The slain pilot's father branded IS “terrorists who know no humanity or human rights”.

“The international community must destroy the Islamic State group,” he said.

IS had offered to spare Kassasbeh's life and free Japanese journalist Kenji Goto, who was later beheaded, in exchange for Rishawi's release.

Rishawi, was sentenced to death for her participation in triple hotel bombings in Amman in 2005 that killed 60 people.

She was closely linked to IS's predecessor organisation in Iraq and was seen as an important symbol for the jihadists.

Jordanian state television suggested Kassasbeh was killed on January 3, before IS offered to spare his life and free Goto in return for Rishawi's release.

Following the airman's capture, another member of the US-led coalition, the United Arab Emirates, withdrew from air strike missions because of fears for the safety of its pilots, a US official said.

“I can confirm that UAE suspended air strikes shortly after the Jordanian pilot's plane went down,” the official told AFP.

“But let me be clear that UAE continues to be an important and valuable partner that is contributing to the coalition,” said the official, who spoke on condition of anonymity.

US President Barack Obama, who had hosted Abdullah in a hastily organised meeting before his return to Jordan, decried the “cowardice and depravity” of IS.

Turkish President Recep Tayyip Erdogan called the brutality of IS “beyond comprehension”.

IS had previously beheaded two US journalists, an American aid worker and two British aid workers in similar videos. It has also killed a second Japanese hostage.