Sixteen children and a female teacher have died after their school bus caught fire in eastern Pakistan, according to local police.
Seven other children were injured in Saturday's blaze which destroyed the vehicle. Gujrat, the city where the incident occurred, is located about 200km southeast of Pakistan's capital Islamabad.
The van was carrying 24 children to a private school when it caught fire, Dar Ali Khattak, the local police chief, said.
"The fire erupted in the vehicle when the children were only a few kilometres from their school," he said.
The blaze was apparently caused by a spark when the driver of the dual-fuel van switched from gas to petrol, Khattak said, adding that the fuel-gas cylinder was intact.
The children were aged between five and 15 years old, he said.
Another police official, Abid Khan, said the driver fled after the fire.
A doctor at the Aziz Bhatti Shaheed hospital said most of the victims were between 10 to 12 years of age and had severe burns.
Private Dunya TV said that about 25 people, mostly children, were on board. Television footage showed the bus completely burnt.
Some private vehicles use cheap gas cylinders for compressed natural gas as fuel, which can burst under pressure.
The government has issued warnings against using unauthorized gas cylinders but has failed to curb the practice.
In other news from Pakistan, two attacks killed nine people in two different areas of the country's northwest on Friday, police said.
In the deadlier of the two attacks, suspected fighters armed with heavy weapons attacked a police convoy in Mattani, 20km south of the main northwest city of Peshawar, killing six policemen and wounding seven others, Shafiullah Khan, senior police officer, said.
In the second attack, a suicide bomber walked up to a vehicle owned by an Afghan religious leader in Peshawar and set off his explosives, killing three people, Riaz Ali Shah, a police officer, said.
The leader, Haji Hayatullah, was not harmed in the attack because he was in a nearby mosque attending Friday prayers.
Hayatullah's driver and guard were killed, Shah said.
A passerby was also killed and two others were wounded, Liaquat Ali Khan, the Peshawar police chief, said.
There are more than one million refugees in Pakistan from neighbouring Afghanistan.
No one has claimed responsibility for the attacks.