The blasts began Thursday at a defence ministry ammunitions depot in the southern region of Jambyl, leaving scores injured and nearby villages evacuated by authorities.

"Unfortunately, four military servicemen died," said defence minister Nurlan Ermekbayev, noting that attempts to contact several other serviceman after the blasts at the facility had failed.

A separate defence ministry statement said that a fifth person had been killed.

The Jambyl regional government said that of more than 80 who received treatment for injuries, 28 remained in hospital with six in serious condition.

On Thursday, President Kassym-Jomart Tokayev had said on Twitter that the injured were soldiers and emergency services workers.

And local authorities said that they were evacuating people from the villages closest to the site of the accident.

On Friday, the defence ministry said that a fire broke out at an ammunitions depot in Jambyl and "quickly spread to storage facilities where engineering ammunition is stored."

Several explosions followed, the defence ministry said.

"The explosions stopped over time, but the fire continues," the statement added.

A video shared on the Telegram messaging app Thursday showed a column of smoke billowing from a fire before a powerful explosion sent flames shooting out.

The defence ministry noted that some of the munitions stored at the Soviet-era depot had been transferred from another depot in the adjacent Turkestan region, where three lethal explosions took place in the last decade.