DENVER — A Middle Eastern diplomat who set off a national terrorism scare when he grabbed a surreptitious smoke in a jetliner's bathroom and then joked about lighting his shoe on fire was released from custody and will likely not face criminal charges.

The scare prompted the military to scramble fighter jets to escort the Boeing 757 to the Denver airport Wednesday night. But no explosives were found on the flight.

Authorities speaking on condition of anonymity said they don't think the envoy was trying to hurt anyone and he will not be criminally charged.

Qatar's U.S. ambassador, Ali Bin Fahad Al-Hajri, cautioned against a rush to judgment.

"This diplomat was traveling to Denver on official embassy business on my instructions, and he was certainly not engaged in any threatening activity," he said in a statement on his Washington embassy's Web site. "The facts will reveal that this was a mistake."

Alison Bradley, a spokeswoman representing the Qatar embassy, said this morning the diplomat, Mohammed Al-Madadi, had been released by authorities after questioning and was on his way back to Washington.

Wednesday's scare came three months after the attempted terror attack on Christmas Day when a Nigerian man tried to blow up a Detroit-bound airliner. Since then, law enforcement, flight crews and passengers have been on high alert for suspicious activity on airplanes.