At least 59 people have died and more than 155 were injured when a nightclub in North Macedonia caught fire in the early hours of Sunday morning.
Officials say about 500 people were at Club Pulse in the town of Kocani, watching a concert by local hip hop group DNK.
"The loss of so many young lives is irreparable, and the pain of the families, loved ones and friends is immeasurable," North Macedonia's Prime Minister Hristijan Mickoski said.
Here's what we know about the blaze.
What caused the fire?
Prosecutors are still investigating, but it appears that sparkling pyrotechnics on stage started the fire.
One video from the event showed the moment the fire began: as the band played on stage, two flares spat white sparks into the air, setting a patch of ceiling alight:
Why was it so hard for people to escape?
There was only one fire exit in the building.
And as hundreds of people tried to leave at once, many were trapped.
Video from inside the club showed chaos as the fire broke out, with young people running through the smoke as the musicians urged them to escape as quickly as possible.
In a Reuters photo from the outside of the building, it appears windows have been boarded-up.
Local media reports also described the nightclub as a former carpet warehouse which only had two fire extinguishers and no fire alarm, North Macedonia's state prosecutor Ljupco Kocevski said.
The ceiling was made of flammable materials and the plasterboard walls were not fire resistant.
A survivor, 19-year-old Marija Taseva, told the Associated Press the windows in the bathrooms had bars on them.
Ms Taseva was at the concert with her sister, who died in the fire.
"We even tried to get out through the bathroom, only to find bars [on the windows]," Ms Taseva said.
"I somehow managed to get out.
"I fell down the stairs and they ran over me, trampled me … I barely stayed alive and could hardly breathe."
There are now a lot of questions about the safety of the building.
The club owners did not have a valid licence, Interior Minister Pance Toskovski told a press conference.
He said the number of people inside the club was at least double its official capacity of 250.
Has anyone been charged over the fire?
So far, about 20 people have been arrested in connection with the fire.
That included members of the band, the son of the club owner and government officials, Mr Toskovski said.
"We have grounds for suspicion that there is bribery and corruption in this case," he told reporters without elaborating.
Mr Mickoski said the club's licence was issued illegally by the economy ministry and promised those responsible would face justice.
"Regardless of who they are, from which institution, from what level, from which party and profession," he said.
Were any Australians at the nightclub in North Macedonia?
There have been no reports of any Australians caught up in the blaze.
Australia does have a consular office in Skopje — its phone number is (+389 2) 3061 114.
However, on the federal government's SmartTraveller advice website for North Macedonia, Australians are told they can access full consular assistance from the Australian Embassy in nearby Serbia.
Where is North Macedonia?
It's an inland country in Europe's west, bordering Greece, Serbia, Kosovo, Bulgaria and Albania.
North Macedonia's capital city is Skopje.
The fire happened in a town called Kocani, about 100 kilometres away from the capital.
[map - data wrapper]With reporting from Associated Press and Reuters
