Unidentified drones affected Belgian airports from Thursday evening into Friday morning, amid an escalating crisis in the European skies.

Liège Airport briefly suspended air traffic twice, around 10 p.m. on Thursday night and again Friday morning around 6 a.m., each time for about an hour, according to public broadcaster VRT. The airport handles mainly cargo, with only a few passenger flights each day.

Brussels airport also had to divert one flight to Amsterdam Thursday night after a drone was detected nearby. Air traffic at Brussels Airport was disrupted by more drone sightings on Tuesday evening.

As the continent’s issues become more widespread — and some European governments have pointed the finger of blame at Russia — drones were also spotted over Antwerp’s port area on Thursday night.

For consecutive nights on Tuesday and Wednesday, drones were also observed above the Royal School for Non-Commissioned Officers in the Flemish city of Sint-Truiden.

Belgium held a National Security Council meeting Thursday, after which Interior Minister Bernard Quintin said that authorities had the situation “under control.”

Defense Minister Theo Francken vowed to strengthen Belgium’s National Air Security Center (NASC). “The NASC in Bevekom must be fully operational by January 1,” he wrote in a social media post.

“This center will ensure better monitoring and protection of Belgian airspace and prepare Belgium for future challenges in air security,” he added.