Brussels is on high alert following the explosions occurred in capital’s airport and metro station killing at least 23 people.

As it was brought to light, Belgian authorities had advanced knowledge of the terrorist attacks in Brussels, but they did not know when and where they would take place.

Belgian authorities have raised the security alert to the highest level following blasts at the Zaventem Airport and Maalbeek Metro station, as RT reports.

Due to the current security situation in Brussels, the city’s transport authority has closed all public transport services.

The explosion comes amid a flurry of counterterrorism activity in the Belgian capital.

A raid this week in Brussels captured Europe’s most wanted man, Salah Abdeslam, suspected Paris terror attacks plotter and aborted suicide attacker.

The Belgian Interior Minister directly linked the explosions to the arrest of Salah Abdeslam saying that the attacks would possible be an act of retaliation.