French police evacuated the Basel-Mulhouse airport on Friday due to an alleged bomb threat.

"For safety reasons, the terminal had to be evacuated and is currently closed," the Basel-Mulhouse EuroAirport said on its website.

However, the airport quickly followed up by saying: "The airport has reopened and flight operations are gradually restarting."

Separately, French officials told the AFP news agency that bomb-disposal experts were on site. 

The air traffic hub, styling itself EuroAirport, is located just several kilometers (miles) away from the Swiss and German border. It welcomed eight million passengers last year.

Olympic Games raise the stakes

The apparent bomb scare comes just hours after a massive attack on the French rail network, and hours before the opening ceremony for the 2024 Olympic Games in Paris.

However, no connection was immediately established between the security incident at Basel-Mulhouse and either of the other events.

Tensions are running high in France as the country welcomes athletes and visitors from across the world due to fears that terror groups could target the event.

dj/rm (Reuters, AFP)