At least 17 people were killed after the bus with 25 on board plunged into a deep ravine in Kohistan district.

Islamabad, Pakistan – At least 17 people have been killed after a bus plunged into a deep ravine in northern Pakistan‘s district of Kohistan, officials say, with at least eight passengers still missing after the accident.

The accident took place late on Sunday night on a remote road winding through steep mountains near the boundary between Kohistan and the Gilgit-Baltistan region, about 200km north of the capital Islamabad, senior police official Raja Abdul Saboor told Al Jazeera by telephone.

“According to the lone survivor, a woman, she heard a loud sound, as if that of a tire bursting as the bus took a sharp turn,” Saboor said.

The vehicle then overturned on the road, before falling into a deep ravine. The survivor was thrown through a window before the bus went over the cliff, he said.

“We will investigate this, but it seems like the bus was going at great speed, and when the tire burst, the driver was not able to control it,” the police official said.

At least 25 people, including the driver, were on board the bus when it entered Kohistan district, police records showed. Rescue officials are continuing to search for the eight missing passengers.

Seventeen bodies have been moved to a government hospital in the town of Chilas, about 75km east of the accident site, to be identified.

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Traffic accidents are common on the mountain roads in the Kohistan and Gilgit-Baltistan region, a mountainous region that is home to some of the world’s highest peaks.

Many residents use passenger buses such as the one that crashed on Sunday to commute to other parts of the country. The sector is poorly regulated, however, and roads often lack guard rails.

The bus that crashed on Sunday was going from Ghizar district in Gilgit-Baltistan to Rawalpindi, near capital Islamabad, a journey of more than 550km that takes more than 18 hours by road.

The World Health Organization estimates more than 29,300 people are killed annually in Pakistan in road traffic accidents, according to a 2016 study.

Government statistics put that number far lower, with Pakistan’s Bureau of Statistics reporting at least 4,448 people were killed in 9,100 recorded accidents across the country in 2015.

Asad Hashim is Al Jazeera’s digital correspondent in Pakistan. He tweets @AsadHashim