Brussels Airport partially reopened on Sunday, 12 days after it was hit by Islamic State attacks, with tearful staff applauding the first departure and an initial trickle of passengers undergoing strict new security checks.

The key travel hub has been closed since two men blew themselves up in the departure hall on March 22 in coordinated blasts that also struck a metro station in the Belgian capital, killing a total of 32 people.

A Brussels Airlines plane bound for the Portuguese city of Faro became the first plane to take off around 11:40 am.

"We're back," Brussels Airport chief executive Arnaud Feist said after watching the plane, decked out with Belgian artist Rene Magritte's trademark birds and clouds, take to the skies.

The restart of the airport has been hailed as the beginning of a return to normal for a traumatized country, but the shadow of the attacks loomed large.

Two big white tents were serving as temporary check-in facilities to replace the blast-hit departure hall, and passengers were asked to come three hours before departure to allow time for tight new security checks.

The first several dozen travelers to arrive on Sunday were met by heavily armed police and soldiers on the access roads to the airport.

There was also a strong security presence inside the tents where passengers walked through metal detectors and had their bags screened before checking in and being allowed to enter the main building.

A father dropping off his son and a group of friends for the Faro flight was positive about the changes. "This is the safest airport in the world right now, isn't it?" he said.

'We can overcome this'

Loukas Bassoukos, a 20-year-old IT student waiting for his flight to Athens, said it felt "a bit weird" to be among the first to return to the bomb-hit airport.

"So many people died here," he said. "But I think we can overcome this. I think we slowly have to start trusting the security controls."

Psychologists were on hand to assist any passengers overcome with emotion.

The number of flights will be stepped up quickly in coming days.

Feist said he expected the airport to start running normally again from late June or early July.

AFP - Reuters