Around 20 people were killed and more than 200 injured when a shallow earthquake hit southwestern Pakistan in the early hours of Thursday, with rescuers trying to reach coal miners reportedly trapped underground.
Many of the victims died when roofs and walls collapsed after the 5.7 magnitude quake struck in Balochistan province, with a power cut forcing health workers to treat the injured using flashlights.
The worst-affected area was the remote mountainous district of Harnai, where a lack of paved roads, electricity and mobile phone coverage hampered rescue efforts.
"We are receiving information that 20 people have been killed due to the earthquake," said Balochistan's home minister Mir Zia ullah Langau.
A woman and six children were among 20 dead, Suhail Anwar Hashmi, a senior provincial government official in Harnai told AFP, adding that "more than 200 people have been injured".
"There are reports that some 15 coal miners are trapped in a mine on the outskirts of the town due to the quake," he added.
It is common in Pakistan for miners to work at night when temperatures are cooler.
A rescue team was being sent to the mine, while helicopters were due to be dispatched to support the rescue effort and evacuate the injured.
Naseer Nasar, the head of Balochistan's Provincial Disaster Management Authority, warned that the toll may rise.
Hospital works by torchlight
The quake caused electricity to fail in the area, with health staff working until dawn without lights in a poorly equipped government hospital.
Before daybreak, "we were operating without electricity with the help of torches and mobile flashlights," Zahoor Tarin, a senior official at the government-run Harnai hospital, told AFP.
"Most of the injured came with fractured limbs. Dozens of people were sent back after first aid," he said, adding that "at least 40 people were received with critical injuries".
"We have imposed an emergency in the hospital and are providing them with medical treatment."
Private individuals were helping rush the injured to hospitals.
The US Geological Survey said the quake had a magnitude of 5.7 and struck around 3 am at a depth of around 20 kilometres.
The earthquake was felt in towns throughout Balochistan, which borders Afghanistan and Iran, including provincial capital Quetta, around 170 kilometres west of Harnai.
Pakistan straddles the boundary where the Indian and Eurasian tectonic plates meet, making the country susceptible to earthquakes.
In 2015, a 7.5-magnitude quake in Pakistan and Afghanistan killed almost 400 people across rugged terrain that impeded relief efforts.
The country was also hit by a 7.6-magnitude quake in 2005 that killed more than 73,000 people and left about 3.5 million homeless, mainly in Pakistan-controlled Kashmir.
A 7.6-magnitude quake in 1935 killed around 30,000 people in Quetta, which at the time was part of British-ruled India.