PRAGUE, June 6, 2024 (BSS/AFP) - Four people were killed and more than 20 injured when an express train crashed head-on with a freight train in the Czech city of Pardubice, officials said Thursday.

The express train from Prague with more than 300 passengers on board was travelling overnight to the Ukrainian town of Chop when it collided with the freight train, which was carrying calcium carbide, a caustic and flammable chemical.

Images from the scene on Czech TV showed a derailed carriage and disoriented passengers, some wrapped in blankets, being ushered into buses.

Prime Minister Petr Fiala described the crash as "a great disaster."

"We all think of the victims and the injured. I express sincere condolences to the bereaved," he wrote on X, formerly Twitter.

The accident happened shortly before 23:00 (2100 GMT) near the main train station in Pardubice, around 100 kilometres (60 miles) east of the capital Prague.

Local emergency services spokeswoman Alena Kisiala told AFP that paramedics had treated 26 injured people.

"Four of them unfortunately suffered injuries incompatible with life," she added.

Ukraine's foreign ministry said two Ukrainian women were among the dead.

The majority of the injuries were described as light, said Interior Minister Vit Rakusan.

The express train, operated by the private Regiojet company, was expected in Ukraine's Chop early on Thursday.

-- Mangled wreckage -

The mangled wreckage blocked the main train corridor connecting Prague with the Czech Republic's second city of Brno and Ostrava for hours, with trains being replaced by buses.

Rakusan said that police were identifying the passengers gathered at the train station after Regiojet had provided the passenger list.

Rescuers said that nine ambulances, two helicopters and more than 60 firefighters had been deployed.

"The rescue work was complicated because the first carriage was deformed. That made it hard to access the injured people," firefighter Pavel Ber told reporters at the site.

Local fire brigade spokeswoman Vendula Horakova told Czech TV the freight train was transporting calcium carbide. However, this did not appear to be a factor in the deaths or injuries.

An investigation into the cause of the accident is under way, said Transport Minister Martin Kupka.

He wrote on X, formerly Twitter, that the accident occurred after the express train ran a red light.

Rail inspectors are looking into the reason, probing a technical defect or a human factor or a combination of both, Kupka said.

Pardubice was also the scene of the worst-ever Czech railway accident in 1960 when 118 people died and around 100 were injured in a head-on collision of two passenger trains just north of the city.

More recent crashes on Czech railways include a 2020 head-on collision of two passenger trains in the west of the country that left two people dead and 24 injured, and a 2021 crash that killed three people and injured around 70.