A day after two explosions in Brussels airport and one at a metro station left 34 people killed and over 200 injured, authorities were examining surveillance footage to nab suspects in Tuesday's explosions, a media report said.
Islamic State (IS) claimed responsibility for the coordinated attacks. Authorities, however, said it was too soon to say for sure whether the terror group was behind the blasts.
In images from surveillance footage, a man wearing light-coloured clothes and a hat pushes a baggage cart through the airport, CNN reported on Wednesday.
Police so far have released photos of three men they say are suspects in the airport attack, standing side-by-side.
Two men, wearing black in surveillance images, are believed to be suicide bombers who died in the explosions in the airport's departure lounge.
Investigators believe the one in light-coloured clothing planted a bomb at the airport, then left. Authorities called him a wanted man and sought public help to track him down.
"The third man left a bomb in the airport, but it did not explode. And we are now looking for this guy," Belgium Interior Minister Jan Jambon said.
A photograph released by investigators shows the three suspects side-by-side.
Federal Prosecutor Frederic Van Leeuw said the two men wearing black in the photograph were likely the suicide attackers.
A break in the investigation may have come from a taxi driver who took the suspects to the airport.
The driver contacted authorities after seeing surveillance footage and gave them the address where he picked the men up, according to two US officials briefed on the investigation.
Investigators found a nail bomb, chemical products and an IS flag during a house search in the Brussels neighbourhood of Schaerbeek, Belgium's federal prosecutor said in a statement.
Hours later, they were still combing through the building for evidence.
