AMMAN, Jordan — Jordanian warplanes bombed Islamic State targets on Thursday, the Jordanian military said, after King Abdullah II promised a “harsh” response to the militant group’s brutal killing of a captured Jordanian pilot.

Jordan has been taking part for months in American-led airstrikes against the group, which has seized large parts of Iraq and Syria. But until now, Jordan had kept its participation relatively quiet, for fear of trouble with Islamist extremists at home.

That changed on Thursday, when the king appeared in state media reports wearing military fatigues, and was filmed paying condolences to the father of the slain pilot as warplanes flew overhead. The jets were said to be saluting the pilot’s family on the way back from the mission against the Islamic State, also known as ISIS or ISIL.

Jordan appeared to be redoubling its participation in the anti-Islamic State coalition, despite the militant group’s threats to shoot down more pilots and its offer of a bounty for any who are captured or killed.