FAF told the Angolan Press Agency that Martins had been informed of the suspension but that no reason had been given.
The agency reported that they have requested further information from FIFA for the reasoning behind the ban.
See the whole story here, courtesy of Inside World Football.
Kicking Back Comments: The US has in the past "benched" FIFA referees (and others), officially, and not officially by not assigning them to matches.
Frankly they have every right to do so for good cause, and should, to prevent even a whiff of impropriety by a referee on, or off the field. For those of us involved with US Soccer, have you read the Code of Ethics for Referees?
If not, you certainly should. It can be found here in the Administrative Handbook. A worthy read for all referees at all levels.