U.S. authorities have identified the third Brussels bomber

Its reported he was on their terror watch list

US authorities know the identity of the third Brussels airport bomber who is believed to be on the run, Sky News has learned.

The man is on the US terror watch list.

The information has been confirmed twice by a Sky News source.

The two brothers involved in the Brussels attacks, Ibrahim and Khalid Bakraoui, were also on the US terror watch list, according to Reuters.

More to follows.