Three more people have been detained over the tragic fire that ripped through a nightclub in Russia's Urals city of Perm, said the Investigative Committee at the Russian Prosecutor General's Office on Saturday.

The detainees included a co-owner of the nightclub, an art director and a private operator in charge of the fireworks setting that started the fire, said Vladimir Markin, a spokesman for the investigative committee. He did not release their names.

The arrest warrant had been issued for one more suspect, the building's lessee, who currently was in critical condition in hospital, said Markin as cited by the Interfax news agency.

Another co-owner of the club, Anatoly Zak, and manager Svetlana Yefremova, were arrested earlier.

At least 109 people died and more than 130 others were injured as fire ripped through the "Lame Horse" nightclub at about 11:15 p.m. Moscow time Friday (2015 GMT) during an indoor fireworks display.

Some 230 people, most of them the club's employees and their relatives, attended the party, which was celebrating the venue's eighth anniversary.

Russian President Dmitry Medvedev accused the bosses of the nightclub of "having no brains and no conscience" and called for harsh punishments.

Meanwhile, he has declared a national day of mourning for the victims on Dec. 7.