(VOVworld) - The fates of a Japanese journalist and Jordanian military pilot remained still unknown on Saturday, a day after the latest purported deadline for a possible prisoner swap passed with no further word from the Islamic State group holding them captive.

A banner with a picture of Jordanian pilot Lt. Muath al-Kaseasbeh, who is held by Islamic State militants, is hoisted by workers near a tent prepared for receiving supporters in Amman, Jordan, Jan. 30, 2015. (Photo: AP)

Jordanian military spokesman Mamdouh al-Ameri said government institutions are working around the clock on the case of pilot Muath al-Kaseasbeh and any developments will be informed in due time. Jordan has said it will only release an al-Qaida prisoner from death row if it gets proof the pilot is alive and so far has received no such evidence from the hostage-takers.  Earlier, an audio message purportedly posted online by jihadis said the pilot, Lt. Muath al-Kaseasbeh, would be killed if Sajida al-Rishawi, the al-Qaida prisoner, was not delivered to the Turkish border by sunset on Thursday, Iraq time. It was not clear from the recording what would happen to Goto if the Iraqi woman was not turned over by the deadline.