A devastating fire has ripped through several high-rise tower blocks in Hong Kong, killing at least 44 people, making it the deadliest in more than 60 years. More than 270 have been reported missing and thousands of residents are in evacuation shelters.
Pictures show several buildings ablaze, and thick smoke billowing into the air, dominating the Chinese territory's skyline.
As night fell, the fire was still burning hours after it was first reported, with more than 760 firefighters deployed to the scene.
Three men have since been arrested on suspicion of manslaughter connected to the fire, according to local media reports, and an investigation has been launched.
Chinese President Xi Jinping has expressed condolences to victims, including a "firefighter who died in the line of duty", state media report.
What caused the blaze is still unclear, but here is what we do know, so far.
Where and when did the fire start?
The blaze broke out at Wang Fuk Court, a large housing complex in Hong Kong's Tai Po district, at 14:51 local time on Wednesday (06:51 GMT).
Wang Fuk Court consists of eight tower blocks, each 31 storeys high. Seven have been affected by the fire, Tai Po district councillor Mui Siu-fung told BBC Chinese.
They provide 1,984 apartments for some 4,600 residents, according to the 2021 government census.
Built in 1983, the tower blocks were undergoing renovations, and the outside of the buildings was covered in bamboo scaffolding and construction netting. Footage shows the fire spreading quickly through the bamboo.
There have been reports by residents in some local media that fire alarms did not sound.
A preliminary investigation found that the rapid spread of the fire was unusual, Hong Kong's security secretary said early on Thursday morning. One of the factors in this was said to be the use of polystyrene - which can be highly flammable - around windows.
Tai Po is a residential district in the northern part of Hong Kong, near the city of Shenzhen on the Chinese mainland.
How serious is the fire?
The Hong Kong fire department has classified the blaze as a level five alarm - the highest in severity.
Within 40 minutes of first being reported, it was declared a level four, but by 18:22, about three and a half hours later, the level was raised again.
It has been 17 years since a level five fire last hit Hong Kong.
Local media reported that explosions could be heard inside the building and fire hoses could not easily reach the higher levels.
The ferocity of the heat was preventing firefighters from entering the buildings to conduct rescue operations, deputy director of fire services Derek Armstrong Chan told media.
"Debris and scaffolding of the affected building are falling down, posing additional danger to our front-line personnel," he said.
It was difficult, he added, to know when the fire would be fully extinguished.
As well as 767 firefighters, 128 fire engines, 57 ambulances and some 400 police officers were deployed.
What do we know about the victims?
The death toll rose significantly early on Thursday morning, from 13 to 36 people.
Just after midnight, Hong Kong chief executive John Lee confirmed 279 people were missing.
Officials reported that the death toll had risen again, to 40, just before 06:00 local time on Thursday. They also said 45 people were in a critical condition in hospital.
Police officers have been helping residents search for family members by using a loudspeaker, local media reported.
Among the dead is firefighter Ho Wai-ho, 37, who was with the service at Sha Tin Fire Station for nine years.
The fire service says it lost contact with him at 15:30, and about half an hour later, found that he had collapsed. He was taken to hospital but declared dead shortly after.
"I am profoundly grieved at the loss of this dedicated and gallant fireman," said Andy Yeung, director of the fire service.
At least one other firefighter is in hospital, the Hong Kong fire service said.
