French president Francois Hollande. Picture: AFP
French president Francois Hollande. Picture: AFP

PARIS — French President Francois Hollande called an emergency meeting of senior government ministers on Tuesday after a series of explosions in Brussels.

Prime Minister Manuel Valls, interior minister Bernard Cazeneuve and defence minister Jean-Yves Le Drian were among those present, according to the president’s office.

The deadly explosions were carried out at Brussels airport earlier on Tuesday by a suicide bomber, Belgium’s federal prosecutor said according to broadcasters VTM and RTBF. A further blast struck a metro station in the capital shortly afterwards.

The blasts at the airport and metro station occurred four days after the arrest in Brussels of a suspected participant in the November militant attacks in Paris, which killed 130 people.

Police had been on alert for any reprisal action in both capitals, which lie about 315km apart across an open border.

Belgium security forces tightened security at nuclear plants across the country after the deadly attacks, the Belga news agency said.

"Surveillance is stepped up with added security measures at nuclear plants," the agency reported.

"Vehicles are being checked with police and army on site," the agency said.

In February, investigators probing the Paris attacks found video footage of a senior Belgian nuclear official at the property of a key suspect.

Dutch police also stepped up security patrols at airports and tightened checks at borders after the attacks in neighbouring Belgium, the security agency said.

Travellers passing through Amsterdam’s Schiphol Airport reported delays and a heavy police presence. Security agencies declined to give details of any further measures taken, but maintained the national threat level at "substantial", one notch below the highest.

Flights were diverted from Brussels to Amsterdam following the attacks and trains heading south to Belgium were subject to indefinite delays, Dutch state railways said.

Reuters, with AFP