Jordan has released an influential jihadi cleric and fierce critic of Isis in the wake of outrage over the group’s brutal killing of the air force pilot who was captured while bombing targets in Syria.

Security sources in Amman confirmed to Reuters that Abu Muhammad al-Maqdisi had been freed from prison – triggering immediate speculation that the intention is to encourage him to speak out against Isis, which now controls large areas of neighbouring Syria and Iraq.

Maqdisi is to be interviewed on the local TV channel, Roya TV, on Friday, the channel said on Thursday night.



Reuters said the release had been ordered by the state security prosecutor. Jihadi sources said that he had in fact been freed before news emerged of the pilot’s death.

Maqdisi, a Palestinian-born preacher who is seen as a spiritual mentor of al-Qaida, was detained last year and denounced Isis publicly for creating its so-called caliphate. He was then detained again last October, allegedly for using the internet to publish jihadi literature.

Jordanians have been outraged by the killing of the downed pilot, Muadh al-Kasasbeh, who was burned alive on camera while locked in a metal cage surrounded by masked fighters. King Abdullah pledged on Wednesday to wage “relentless war” on Isis, though the country’s military reach remains limited and it is unlikely to be able to mount ground attacks on the Isis stronghold in Raqqa in northeastern Syria, where the 26-year-old pilot was murdered.

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Jordan has made clear that it sees the fight against Isis as an ideological struggle which requires undermining its spurious claim to legitimacy. The immolation of Kasasbeh has been widely denounced as un-Islamic, though the group issued a fatwa supposedly justifying it on the grounds that the bombs of the US-led coalition were burning innocent Muslims.

Maqdisi acted as the spiritual guide to the Jordanian Abu Musab al-Zarqawi, the former leader of al-Qaida in Iraq – the forerunner of Isis – but later disowned him for targeting civilians indiscriminately in the Amman hotel bombings which killed 57 people in 2005, dubbed Jordan’s 9/11.

“If Maqdisi has agreed to condemn the killing of the pilot, reflecting the revulsion that has been felt all over Jordan, then that would certainly make sense of his release,” one Amman analyst said.

Queen Rania of Jordan, right, offers her condolences to the wife of the murdered pilot. Photograph: Petra/Reuters

Maqdisi was also involved in abortive efforts to negotiate the release of the US aid worker and Muslim convert Peter Abdul-Rahman Kassig before he was beheaded by Isis, a Guardian investigation revealed. The Jordanian government never responded to questions about the timing of his re-arrest.

Jordan said on Thursday that it had carried out new air strikes against Isis targets, the returning fighter jets flying over Kasasbeh’s home in Karak governorate while King Abdullah was there offering his condolences to the Kasasbeh family.

“We will not let this crime of killing our pilots with the horrific way it was done pass without punishment,” said government spokesman Mohamed al-Momani. “These people will be punished.”