At least 43 people were injured in multiple blasts at a munitions factory in the Russian city of Dzerzhinsk on Saturday, Russian media reported.
Among those requiring medical attention were workers at the plant and residents of nearby houses, the regional health department told the Interfax news agency. Four people suffered severe injuries, 15 in total had to be hospitalized.
The explosion happened at the "Kristall" factory in Dzerzhinsk about 400 kilometers (250 miles) east of Moscow, in the Nizhny Novgorod region.
A local health ministry official quoted by the TASS news agency said 42 people had suffered light or moderate injuries, an increase on an earlier estimate.
Of the injured, 14 had to be hospitalized, but no one had been killed, said the spokesman.
Earlier, health ministry officials told news agencies that the wounded had "shrapnel wounds of mild and moderate severity" and that they were receiving medical assistance.
The force of the blast damaged five factory buildings and 180 houses nearby.
The deputy governor of the Nizhny Novgorod region, Dmitry Krasnov, told Russian state television that two people were missing.
Russia's Investigative Committee said it had opened an investigation into potential violations of industrial safety at the plant.
Local emergency services told news agencies that more than 300 people and 50 technical vehicles were taking part in cleaning the plant following the explosion.
Representatives of Kristall told Interfax that five people were working in the area where the explosion occurred and were safely evacuated.
There was no information yet on where the injured were at the time of the blast.
Local firefighters told agencies they had no information about any more people still inside the plant, which was set up in 1953.
"There was an explosion in one of the workshops, followed by a fire of around 100 square meters," a spokesman of the local emergency ministry told news agencies.
Images on social media showed a large cloud of smoke billowing from the building after the explosion.