Extreme hot weather has prompted the Russian Army to temporarily suspend the use of some incendiary ammunition during military training exercises, according to a military spokesman.

Recent blasts caused by extreme heat killed six servicemen at a military firing range in south Siberia’s Altai Territory and an officer at a military training ground in central Russia’s Saratov region.

Russian Army spokesman Colonel Oleg Yushkov said tracer, incendiary and illumination munitions have been temporarily prohibited during military training exercises due to the jump in temperatures, according to RIA Novosti.

“Military personnel are prohibited from remaining in the sun for a long time and have been provided with additional security measures,” Yushkov said.