An explosion has hit a major gas pipeline in eastern Ukraine, a day after Moscow decided to reduce supplies to Kiev over allegedly unpaid bills.

The blast struck the Urengoy-Pomary-Uzhgorod pipeline, also known as the West-Siberian Pipeline, in Ukraine's eastern Poltava Region.

"The gas explosion went off one kilometre away from the village of Iskovtsy," a spokesperson for the local police told Russia's Itar-Tass news agency.

"According to available reports, no people were injured in the gas blast, fire-fighting efforts continue."

Flames reached up to 200 metres high, the regional office for the Ministry of Internal Affairs said.

A huge fire raging in a field crossed by the pipeline, which carries gas from Siberia to Europe, could be seen in videos purportedly from the scene which were posted on YouTube and social media.

Fire crews tuned off Pipeline faucets and were fighting the flames, local media reported.

The causes of the explosion were not immediately clear.

Urengoy-Pomary-Uzhgorod is one of the largest pipelines in the world, running for 4,451km and carrying more than 100bcm of gas per year.

Its Russian section is operated by Gazprom while the Ukrainian part is operated by the state-run UkrTransGaz.

Yesterday, Russian state-energy giant Gazprom announced a cut in gas supply to Ukraine, saying Kiev will only receive the gas that it has paid for in advance.

The reduction in supplies to Ukraine could lead to disruption in gas deliveries to the European Union, which relies on Russia for a third of its gas needs. Around half the gas channelled from Russia is transported via Ukraine.

The move came with relations between the two neighbours at a historic low, after Russia annexed Crimea and allegedly supported the ongoing separatist insurgency in eastern Ukraine.

The Poltava Region, where the explosion has been reported, is not one of those currently affected by fighting between government forces and pro-Russian separatists.