MOSCOW, March 26. /TASS/. A security guard switched off a fire alarm system at the shopping mall in the Siberian city of Kemerovo, the scene of a deadly blaze, Russia’s Investigative Committee Spokeswoman Svetlana Petrenko said on Monday.

The man, who worked for a private security firm, may be detained as the fifth suspect in the criminal case, Petrenko said.

Four persons have been detained and questioned - technical director of the company owning the building, the tenant of a facility where the source of the fire was believed to be located, an employee and the head of an organization servicing the fire alarm system, she said.

Head of the Russian Investigative Committee Alexander Bastrykin, who arrived in Kemerovo, is personally overseeing the criminal investigation.

The IC spokeswoman noted that serious violations had been made during the building’s commissioning.

"Safety regulations were severely violated while commissioning the shopping mall, as well as during its operation. In particular, emergency exits were locked," she said, adding that investigators were also looking into reports about other violations.

The fire at the Zimnyaya Vishnya (Winter Cherry) shopping mall in central Kemerovo erupted on Sunday on the top floor of the four-storey building engulfing an area of some 1,500 square meters. According to the latest data, 64 people were killed, many of them children, and 52 others sought medical assistance. Twelve people remain in hospital and 40 others receive medical assistance on an outpatient basis.