Why did a bomb alert in Calais hold up Eurostar trains?

A bomb alert hit the rail station at Calais-Fréthun, on the French Channel coast. The station sits just outside Calais, beside the Eurotunnel car terminal in Coquelles. Security services searched it, and checks were still under way when the first reports appeared.

The Pas-de-Calais prefecture posted on X: This risks affecting traffic in the area. Be careful. The alert put rail services nearby at risk.

The short answer is that Eurostar's website expected delays of 30 minutes to an hour. The articles do not say whether the threat was credible, whether a device was found, or when services resumed at the station.