MOSCOW, June 21. /TASS/. The number of people injured in Tuesday’s fire-igniting blast at a gunpowder factory outside of the southern Russian city of Tambov has increased to 13, all of whom have been hospitalized, the local emergency services said in a statement.

According to first responders, there were 18 casualties altogether, including five dead and 13 injured in the fire, although the blaze was contained to an area of around one square meter and extinguished within minutes.

Initially on Tuesday, the plant told TASS that four people were killed and eight more sustained wounds. Later in the day, the regional branch of Russia’s Investigative Committee said the death toll had risen to five.

The Tambov Region emergency services reported an explosion at the gunpowder plant in Kotovsk about midday on Tuesday. Regional Governor Maxim Yegorov said that the incident was allegedly caused by human error, with no threat being posed to other plant employees or residents of adjacent localities.

Local investigators have launched a criminal probe on charges of safety violations. The local branch of Rostekhnadzor, Russia’s industrial safety watchdog, is also looking into the causes of the incident.