Twelve people died and six were critically injured on Monday when a van collided with one of Islamabad toll plaza's walls, took multiple tumbles before catching fire, according to Islamabad Deputy Commissioner (DC) Hamza Shafqat.

The automobile, a Toyota Hiace, was carrying 18 passengers — comprising both men and women — from Sargodha to the capital when it met the accident.

Nine passengers died on the spot, while three others succumbed to their injuries later. The injured were shifted to the intensive care unit of the Pakistan Institute of Medical Sciences (Pims), a Rescue 1122 official said.

Islamabad deputy commissioner said that of the dozen dead, four have been identified so far. He quoted Naseerabad police station officials as identifying "brake failure" as one possible cause of the accident.

However, he could not say with certainty whether "speeding or the bursting of the gas cylinder" triggered the tragedy.

DC Shafqat said that since the accident did not take place within the limits of Islamabad, therefore, Motorway Police have been told to conduct an inquiry.