More than 30,000 people have been evacuated in the central Vinnytsia region of Ukraine after a huge arms depot storing missiles caught fire and exploded, in what authorities said was a possible act of "sabotage".

The fire, near the town of Kalynivka, about 200km south-west of Kiev, injured two people, Ukraine's State Emergency Service said in a statement on Wednesday. There were no reports of any fatalities.

More than 180,000 tonnes of munitions were believed to have been stored at the depot, including projectiles for various rocket-launch systems alongside ageing Cold War-era munitions.

READ MORE: Munitions depot went up in flames in Ukraine

"People suffered heavy damage," a local resident who gave her name as Antonina told AFP news agency. "Some homes had their windows and doors completely blown out," she said.

The flames caused artillery shells at the facility to explode one after the other in spectacular but harrowing orange balls of fire that lit up the night sky and shook the ground.

Prime Minister Volodymyr Groysman called for a thorough investigation into the incident, as he assured the public that the blaze had been brought under control.

"This is the arsenal of the Ukrainian army, and I think it was no accident that it was destroyed," Groysman said.

"We need to make sure that the guilty are held responsible."

Officials shut down surrounding airspace as a precaution to keep exploding missiles from hitting passing commercial jets.

Ukraine's emergency service began using two An-32 military cargo planes to douse surrounding forests with water to localise the raging flames.

The fire first started on Tuesday, which was President Petro Poroshenko's birthday.

Poroshenko underscored the seriousness of the situation by telling his top military brass and Groysman, the prime minister, to report to him directly after visiting the site.

The blaze and accompanying explosions appeared similar to an incident in March at a munitions depot in the eastern Kharkiv region, said Groysman.

About 20,000 people were evacuated during the Kharkiv incident.

Kiev had blamed that deadly blast on Moscow and its Russian-backed armed groups fighting Ukrainian forces in the war-wracked east - a charge both denied.

The Ukrainian military has been fighting Russian-backed separatists for the past three years in Ukraine's two eastern-most regions, Donetsk and Luhansk, which border Russia.

About 10,000 people have been killed in the conflict, which erupted after Ukraine overthrew its pro-Russia president in early 2014.