BRUSSELS: Bomb-damaged Brussels airport held a drill for a partial restart on Tuesday but warned it could take months to reopen fully, as under-fire Belgian authorities hunted for a suspect still on the run a week after the deadly attacks.

As Brussels struggled to get back on its feet, criticism of Belgium’s handling of the case mounted after the sole suspect to be charged over the airport and metro attacks was freed for lack of evidence linking him to the carnage.

Prosecutors had charged the suspect, known as Faycal C., with “terrorist murder” and were investigating whether he was the third airport attacker who fled after his bomb did not detonate.

With his release on Monday, the hunt was back on for the so-called “man in the hat” seen in CCTV footage next to the two Daesh suicide bombers at Zaventem airport.

The airport, closed since the blasts wrecked the departure hall, was staging a test run Tuesday involving hundreds of volunteer staff to determine if it was ready to resume flights, albeit in a very limited capacity, from Wednesday. A temporary check-in facility has been set up and passengers will be subject to extra security checks when it does open.

Brussels Airport chief executive Arnaud Feist also warned that even if the airport did reopen Wednesday, it would only be at 20 percent capacity, handling 800-1,000 passengers an hour. For a full return to normal, “we will have to wait for months,” Feist told L’Echo daily.

Security around Zaventem was tight for the drill, with soldiers and police stopping and checking all vehicles headed for the airport.