Dozens of people have been stretchered out of the airport in Brussels after two explosions occurred there earlier on Monday, according to eyewitnesses.

Two explosions occurred at the airport Brussels, Belgium.

Federal police at the airport at Zaventem told CNN that “there has been an explosion” and “something has happened.”

The Brussels airport tweeted that there have been two explosions and said that “the building” is being evacuated.

Anthony Barrett said he heard something at about 8 a.m. local time from his hotel across from the terminal building.

“When I opened the curtains and looked out, I could see people fleeing,” he told CNN.

He said he’s seen about 19 or 20 stretchers carrying people so far. Luggage trollies were also being used to transport the wounded.

“It’s clearly a very serious incident,” he said.

It’s unclear what caused the explosions, or if they’re related to terrorism.

The airport is currently being evacuated and a disaster plan has been initiated, according to CNN affiliate RTL. Passengers have been directed to the runways.

Witnesses told RTL at least one of the two explosions took place in the airport's departure hall.

The incident comes after Salah Abdeslam, a man who authorities say was involved in the Paris terror attacks last year, was arrested in the Brussels suburb of Molenbeek on Friday.

•Photo courtesy of CNN shows smoke billowing from the airport Brussels, Belgium, after the explosions.