The agency said shots were fired and there were shouts in Arabic shortly before the explosions, Reuters reported.
The blasts occurred four days after the arrest in Brussels of a suspected participant in November militant attacks in Paris that killed 130 people. Belgian police had been on alert for any reprisal action.
Unconfirmed reports say at least 11 have been dead and 20 others injured at the Brussels airport explosion.
Social media showed pictures of smoke rising from the departure hall where windows had been shattered by the blasts. Passengers were seen running away down a slipway.
Meanwhile, unconfirmed reports of an attack at a Brussels metro station close to the EU buildings at Maalbeek.
The entire Metro system in Brussels has been closed,reports added.
