A suspect sought by police in November's Islamic State attacks in Paris and last month's Brussels bombings as well has been arrested.
Mohamed Abrini was one of several suspects nabbed during raids by Belgian police in Brussels on April 8.
Abrini, a 31-year-old Belgian, was "more than likely" the "man in the hat" seen on security camera footage at Brussels airport on March 22 with two suicide bombers, Belgian media said.
If confirmed, the arrests could mark a success for Belgian security services, which have faced fierce criticism at home and abroad since Brussels-based militants organized the attacks that killed 130 people in Paris on November 13.
Investigators so far had not publicly made a link between Abrini and the Brussels attacks, which left 32 people dead at the Belgian capital's airport and a subway station.
Three suicide bombers also died in the March 22 attacks, while a fourth suspect fled after leaving an explosive device at the airport.
The fugitive came to be known as "the man with the hat," based on video surveillance images of him.