At least 19 people have been killed and dozens injured after a speeding bus veered off a major expressway in central Bangladesh and plunged into a ditch.

The death toll could rise further as some of the injured passengers are in critical condition, according to Anowar Hossain, a police official of Shibchar, where the crash occurred.

The city is 80 kilometres away from the capital Dhaka.

The bus, carrying more than 40 passengers, fell about 9 metres into a roadside ditch after breaking through the railing of the newly-built Padma river bridge expressway, Mr Hossain said.

The driver, who was killed, appeared to have lost control of the vehicle after the tyre of the bus burst, he said, and the cause of the accident is under investigation.

Road accidents — often blamed on reckless driving, old vehicles, and poor safety rules — are common in Bangladesh and kill thousands each year.

In 2018, a series of massive student protests sparked by the death of two teenagers forced Prime Minister Sheikh Hasina's government to act.

It approved raising the maximum prison time to five years from three for causing death by reckless driving.

Reuters