A fire has killed 41 inmates in an overcrowded prison block in Indonesia's Banten province, a government minister said on Wednesday.
Scores more people were injured in the blaze, which police said may have been caused by an electrical fault.
Most inmates were asleep at the time.
Indonesian law and human rights minister Yasonna Laoly said the fire broke out at 1.45am local time on Wednesday in Block C of Tangerang Prison, about 33 kilometres from the capital Jakarta.
Firefighters extinguished the blaze – which was mostly contained within the block that housed prisoners jailed for drugs offences – and evacuated inmates.
Television footage showed a massive fire raging through the prison block, with thick smoke billowing from the building as firefighters raced to put out the flames.
“Forty-one inmates died, eight were badly injured and 80 others sustained minor injuries,” Jakarta police chief Fadil Imran said.
Two foreign nationals – from South Africa and Portugal - were among the inmates killed, Mr Laoly said.
Authorities were still investigating the cause of the incident but suspect an electrical fault may have been to blame.
“I have checked the scene. Based on early observation, it is suspected [the fire] happened because of a short circuit,” Mr Imran said.
The prison department's website showed that the jail had just over 2,000 inmates – more than three times as many as it was designed to hold.
The block where the fire broke out had a maximum capacity of 40 inmates but housed 120, penitentiary directorate general official Rika Aprianti told Metro TV.
Overcrowded, unsanitary conditions are common in Indonesian prisons, which contain about 270,000 inmates, and jailbreaks are frequent.
In 2019, at least 100 prisoners escaped from a jail in Riau province, Sumatra, after a riot and fire broke out.
In April last year, Indonesia released some 29,000 inmates in a bid to stop Covid-19 from rampaging through the prison system.