(Brussels): A man has been arrested amid an anti-terror operation sparked by a bomb alert at a shopping centre in Brussels, authorities say.

The man called police earlier in the morning and said he was wearing explosives, Belgian media report.

Several reports citing security services now say that no explosives were found on him.

Streets around the City 2 shopping centre have been closed off and a bomb disposal unit is at the scene.

"For the moment, the situation is under control," Prime Minister Charles Michel said after a meeting the national crisis response centre, according to the Le Soir daily.

He said security services remained "extremely vigilant".

Belgium's terror alert level remains at three, one step down from a maximum level of four.

City 2 tightened security measures last week in response to media reports of a heightened threat to shopping centres based on an internal police memo, Le Soir reports.

Bomb attacks on Brussels airport and the city's metro killed 32 people in March and were claimed by the Islamic State group.