Three owners of a nightclub in Romania where 31 people died in a fire on Friday have been arrested for suspected manslaughter, prosecutors say.
The men were questioned for several hours about the Bucharest blaze, which started when fireworks were set off by a band performing at the venue.
Witnesses and Romanian media have queried safety standards at the club.
They are concerned about the lack of an emergency exit and the use of flammable material to soundproof the building.
The three arrested men, aged between 28 and 36, were questioned for several hours on Monday about the fire, the AFP news agency reported. It said one of those being held is a barman with shares in several clubs.
None of those arrested has made any comment.
The club is suspected of not being authorised to hold concerts or to stage pyrotechnic displays, Interior Ministry Secretary of State Raed Arafat is quoted as saying. Prosecutors are also inquiring into who should have insured the premises.
The trio – named as Costin Mincu, Alin George Anastasescu and Paul Gancea – are accused of allowing the club to be overcrowded and of not taking sufficient steps to ensure it had enough emergency exits.
In a separate development the owners of three other night clubs admitted they had recklessly failed to uphold safety standards, the AP news agency reported.
It said that all three have apologised for their actions, with one confessing that he had put thousands of lives in danger and another conceding he had been “ignorant and irresponsible”.
Friday’s fire broke out at about 23:00 (21:00 GMT) at the Colectiv club, which was hosting a free rock concert by the band Goodbye to Gravity. Up to 400 people are thought to have been inside.
Survivors say the fireworks caused the ceiling and a pillar to catch fire and produce heavy smoke.