Six people died when a Croatian passenger train derailed yesterday near the southern Adriatic city of Split at the height of the summer tourist season, police said.

Twenty people were seriously injured, a police spokeswoman in Split said. Some 50 people suffered light injuries, state television reported, citing hospital sources.

The train, travelling from the capital Zagreb, derailed shortly after midday as it approached Split, an ancient city whose core is built into the remains of Roman Emperor Diocletian's palace.

The train was carrying around 90 passengers, on a route often used by holidaymakers heading for the coast.

Rough terrain was hampering rescuers' efforts. Split hospital appealed for blood donors as a precaution, state television said.

"Emergency teams were immediately dispatched to provide help and determine the cause of the accident," the state rail agency Hrvatske Zeljeznice said in a statement.