Air traffic controllers at Brussels Airport continue strike for the second day, forcing the cancellation of flights in the Belgian capital which is still reeling from a deadly attack last month.
The strike action over pensions and staffing has been brewing for months, crippling one of Europe's busiest airports which reopened on April 3 with limited capacity.
Brussels Airport is restricted by tight security and temporary structures erected after bombs destroyed the departure hall on March 22.
Two men blew themselves up in the departure hall in coordinated blasts that also hit a metro station in the Belgian capital. A total of 32 people lost their lives in the attacks.
After the reopening, only passengers with tickets and ID documents have been allowed into the makeshift departure hall while their bags will be checked. Once inside, passengers will also undergo usual security checks.
A spokesman for the airport said that 50 of the 400 scheduled flights have been canceled so far until midday on Wednesday.
Following the Brussels bombing and November 13 Paris attacks in which 130 people were killed, several European cities have heightened security.
On Tuesday, Dutch security officers partially evacuated Amsterdam's Schiphol Airport and arrested one man after reports of a suspicious package.
Heavily armed military police, wearing body armor and ski masks, patrolled Schiphol for four hours while explosives experts checked the suspect's luggage.
The bomb squad found nothing in the luggage of the man, but he is still held in custody.
The tense operation left many passengers stranded outside the airport. However, flights were unaffected and trains continued running to the airport's underground station.