MOSCOW — Fire tore through an ammunition depot in the central Russian region of Udmurtia, causing shells to explode all day Friday. More than 28,000 people were evacuated from their homes.

Two elderly people living in the vicinity died of heart attacks apparently connected to stress from the explosions, the republic's health minister Vladimir Muzlov said Friday, according to Russian news agencies.

The Russian Emergency Situations Ministry said 52 people asked for medical help and 25 of them were hospitalized following the blaze and explosions that started late Thursday at the arsenal some 900 kilometres east of Moscow.

The Interfax news agency said that 106 of the arsenal's 152 buildings were destroyed by the fire and explosions. Several fire aircraft were pouring water on the area to prevent the blaze from engulfing the surrounding forests.

Explosions broke windows in buildings as far as 10 kilometres from the arsenal.

The cause of the blaze was not immediately determined. It occurred just days after a fire that erupted at a similar ammunition depot in the nearby region of Bashkortostan, causing extensive damage and injuring 12 people.

Russian President Dmitry Medvedev ordered Defence Minister Anatoly Serdyukov to find and punish those responsible. "We will have to take off their epaulettes," Medvedev said.

Deputy Defence Minister Gen. Dmitry Bulgakov told the ITAR-Tass news agency that the arsenal stores a small number of artillery rockets, but they are not in danger of exploding.