At least 56 people, including 18 children, have been killed after a passenger bus collided head-on with a lorry carrying goods in southern Pakistan, officials said.

The accident happened on Tuesday near the city of Khairpur, 450km north of Karachi, the capital of southern Sindh province.

"The Karachi-bound passenger bus, which was coming from northwestern city of Swat went on the wrong side of the road and collided head-on with a goods container, killing 56 people," senior local police official Nasir Aftab told the AFP news agency.

He said 18 passengers were injured in the accident, adding that those killed in the crash included 17 women and 18 children. Th rest were men.

A senior doctor at the Khairpur civil hospital confirmed the death toll and said the condition of three of the injured was critical.

Pakistan has an appalling record of fatal traffic accidents due to poor roads, badly-maintained vehicles and reckless driving.

The emergency services' recovery equipment is basic and when crashes happen away from major towns, as they often do, rescue efforts can take some time, reducing injured passengers' chances of survival.

In April, a bus smashed into a tractor-trailer in a high speed collision in Sindh, killing 42 people, while in March a horrific crash between two buses and a petrol tanker left 35 dead, with many burned alive when the fuel ignited.

The mountainous areas of Kashmir and the north, where drivers career around narrow hairpin bends over deep ravines with scant regard for safety, are particularly prone to accidents.

Three crashes in the space of 10 days in March in Kashmir and the northwest left a total of 46 people dead.

Source: Agencies