Hundreds of passengers were evacuated from two Eurostar trains Friday in Belgium after breakdowns left them without air conditioning in the midst of a sweltering heatwave, the country’s rail agency said.

A train from Cologne to Paris carrying about 400 people ground to a halt near the city of Leuven in the morning due to a technical issue of yet unconfirmed nature, Belgium’s Infrabel told AFP.

“The passengers were evacuated safely” and provided with bottles of water, before being transferred onto a replacement service, a Eurostar spokesperson said.

Local authorities and the Red Cross aided the operations, the company said.

Three passengers were taken to a hospital in Leuven as a precaution, but their condition was not considered serious, Belgium’s Belga news agency reported.

Then in the afternoon a train running on the Paris to Amsterdam line similarly came to a stop near the town of Duffel, south of Antwerp, due to a power supply problem caused by a broken overhead line.

Almost all of Belgium was under red or orange heatwave alerts Friday, with temperatures well exceeding 35 C in several regions and set to reach 40 C in some parts of the country’s east.

Eurostar apologised to the affected passengers.