For some unexplained reason, the FBI allowed the two witnesses in the New YorkCity bombing to fly back to Egypt, according to law enforcement officials.

However, though the two men are not currently in custody, the FBI reportedly knows who they are and their whereabouts. Law enforcement officials say they are Egyptian pilots and are presumed to have returned to Egypt. They are still considered witnesses, not suspects.

Authorities on Tuesday released new photos of the men to the public.

JUST IN: Men who walked away with bag containing pressure cooker bomb in NYC are NOT in the U.S. but @FBI now knows who and where they are. pic.twitter.com/tkoI4GXcWs — Good Morning America (@GMA) September 28, 2016

"I think they were more interested in the bag, not what they were taking out," said Jim Watters, chief of the New York Police Department's counter-terrorism unit.

"They're not in any jeopardy of being arrested," Watters said. "We have no reason to believe they're connected."