A bus travelling to Pakistan's southern city of Karachi has collided with a tractor-trailer, killing at least 42 people and injuring 17 others. 

Among those killed in Sunday's accident were 14 children and 13 women, the AFP news agency quoted the police as saying.

The accident happened in the town of Sukkur, 425km north of Karachi in the southern province of Sindh.

Fida Hussain Shah, a senior Sukkur police officer who gave the casualty figure, said the bus driver was killed on the spot while the driver of the tractor-trailer was wounded.

Police said the cause of the accident was yet not clear. All the dead and injured were riding in the bus, apart from the tractor driver.

Sharjeel Kharal, another senior police official, confirmed the incident.

Most of the injured were in critical condition and many were transferred to a hospital in Karachi after initial treatment in Sukkur.

Among the dead were six members of one family travelling in the bus. Two more family members were injured while two were unhurt -- Maryam Bibi, 18 and her six-year-old brother Samad.

"We were ten members of one family, six of them died and two were injured," a weeping Bibi said as she recounted the accident.

The family was travelling to visit other relatives in Karachi, she said. Pakistan has one of the world's worst records for fatal traffic accidents due to poor roads, badly maintained vehicles and reckless driving.

Source: AFP