About 130 remained hospitalized, many in critical condition, with injuries from the early Saturday blaze, which witnesses said was sparked by onstage fireworks that shot into the decorative twig ceiling of the Lame Horse club in the Ural Mountains industrial city of Perm. Shocked and grieving relatives on Sunday began to bury the victims of the disaster.
The federal Investigative Committee said the suspects - the club's owner, the executive director, the artistic director and a businessman hired to install pyrotechnics on the night of the blaze - were ordered taken into custody Sunday by Leninsky District Court.
The commitee's Web site said they were suspected of negligence causing multiple deaths and violating fire safety rules causing multiple deaths.
Russian news agencies named the owner as Anatoly Zak. The pyrotechnics expert was named as Sergei Dergunov by his lawyer, Yekaterina Golysheva.
Mourning residents were indignant over the alleged negligence, which President Dmitry Medvedev also criticized in a nationally televised videoconference on Saturday.
Emergency Situations Minister Sergei Shoigu said that the club managers had been fined twice in the past for breaking fire safety regulations, which he did not specify. Russian clubs and restaurants often cover ceilings with plastic insulation and a layer of willow twigs to create a rustic look, one of many uses of combustible materials in buildings by businessmen who bribe officials to look the other way.
Nadezhda Zhizhina placed flowers on the icy ground outside the Perm City Morgue in memory of her 21-year-old son, Sergei.
She said she wasn't expecting the compensation officials have promised to other victims' relatives because Sergei earned pocket money at the club as an unofficial administrator.
"I can't even imagine what to do," Zhizhina said, weeping. "He was a golden boy."
She said Sergei's wife, Yulia, was eight months pregnant.
The disaster has shaken this town of over 1 million, mobilizing even those who didn't lose relatives - such as Marina Dryonina.
"This is nothing but criminal negligence," she said. "A terrible tragedy for our town."
Many victims were trapped in a panicked crush for the exit as they attempted to escape the flames and thick black smoke.
Emergency Ministry spokeswoman Darya Kochneva said a man flown to a Moscow hospital had died of severe burns, bringing the toll to at least 112.
Enforcement of fire safety standards is infamously poor in Russia and there have been several catastrophic blazes at drug-treatment facilities, nursing homes, apartment buildings and nightclubs in recent years. The nation records up to 18,000 fire deaths a year, several times the per-capita rate in the United States and other Western countries.
Medvedev demanded that lawmakers draft changes to toughen the criminal punishment for failing to comply with fire safety standards.
Monday has been designated a national day of mourning, with entertainment events and television programs canceled.