Four people have died and more than 20 were injured when a passenger train collided with a freight train in the Czech city of Pardubice, emergency and government officials say.

At least 20 people suffered light injuries and another three were seriously injured, Interior Minister Vit Rakusan said.

Rescue services were on the scene, the police said, and were helping passengers.

The crash occurred after 11pm on Wednesday evening, local time, on the country's main rail corridor from Prague to the east.

Fire and rescue services said more than 300 passengers were on board the train, which the Railway Administration said was travelling overnight from Prague to Kosice in eastern Slovakia.

The passenger train was operated by rail company RegioJet, Martin Netolicky, governor of the Pardubice region, said on Facebook.

Footage after the crash on news website idnes.cz showed at least one carriage off the track, while police showed on their X social media account a line of emergency service vehicles and a helicopter.

Czech Television cited a fire brigade spokesperson saying the freight train was carrying calcium carbide, although the first two wagons were empty, so no leak occurred.

Transport Minister Martin Kupka, who travelled with the interior minister to the crash site, told a televised briefing an investigation into the accident was beginning and it was too early to speculate on its cause.

Prime Minister Petr Fiala expressed his condolences to the victims on X.

Reuters