At least 20 people including women and children were killed Monday when a lorry toppled over and shed its load of coal onto a passenger van in Khairpur district of Sindh, police said.

Seven people were injured in the accident in Khairpur district in Sindh province.

A senior district police official said the truck was trying to overtake the van when it toppled and crushed the other vehicle.

"The van (was) buried under the coal and at least 17 people including children and women died on the spot," Azfar Mahesar told AFP.

Eight injured people were rushed to hospital but three subsequently died, said hospital doctor Ghulam Jafar.

Several of the bodies were badly crushed by the coal and so far just 10 have been identified, he added.

Pakistan has one of the world's worst records for fatal traffic accidents, due to poor roads, badly maintained vehicles and reckless driving.