The storage facility was located in Chernihiv, 76 kms (109 miles) east of the Ukrainian capital Kiev.
A statement by the emergency services reads: “About 10,000 people were evacuated.
“From 04:22 am (02.22 BST) the airspace within a radius of 20 km has been closed.
“The movement of rail and road transport is suspended.”
There have been no reports of any casualties at this stage.
It is also not clear whether the explosions were an accident or a sabotage.
According to reports on social media, the powerful explosions smashed doors and windows in nearby areas.
Pictures emerged showing the night sky lit up by the bright explosions.