At least 20 persons were killed and more than 150 injured in northern India when nearly a dozen coaches of a passenger train got derailed, said media reports.

About 13 bogies of Delhi-bound Kalka Mail from Howrah derailed this afternoon near east cabin of Malwa station, nearly 120 kms from Lucknow, the capital of north Indian state of Uttar Pradesh.

The accident occurred when the driver of the train applied emergency brakes, said AK Jain, additional director general of the railway police. He said he feared the death toll would go up.

State-run monopoly Indian Railways carries around 30 million people every day, but has a patchy safety record because of ageing infrastructure.

'Twenty bodies have been recovered...it won't be surprising if more than 50 people are killed as many bodies are still trapped inside the mangled coaches,' special director general of police Brij Lal said.