An explosion destroyed a 30-metre section of the trunk gas pipeline taking Russian gas across Ukraine to Europe on Monday, but Russian gas export monopoly Gazprom said flows of gas were unaffected.
"There has been no reduction in gas supplies to European customers," Gazprom said in a statement.
Gazprom customers in eastern Europe reported no disruption to supplies.
A spokesman for Ukraine's Emergencies Ministry initially said the blast had stopped the flow of gas to Europe, which gets a quarter of its gas from Russia. Another spokesman later said a by-pass pipeline had come on stream and flows to Europe were unaffected.
Gazprom said it was fully meeting its obligations to supply customers and its gas flows via Ukraine had not been disrupted.
In Brussels, the European Union noted no disruptions and said it was monitoring developments with Ukrainian officials.
A statement said Energy Commissioner Andris Piebalgs was in close contact with Ukrainian Fuel & Energy Minister Yuri Boiko "to find out the causes of the explosion and its effects in the supply of gas to the European Union".
A spokesman for Ukraine's Emergencies Ministry, Oleksander Trigub, said the blast occurred at 2:25 p.m. (12:25 p.m. British time) on the trunk pipeline to Europe, near the village of Luka.
The pipeline takes gas from Gazprom's Arctic Urengoi gas field via Pomary in the Urals to Uzhgorod on Ukraine's border with Slovakia.
POWERFUL BLAST
The cause of the explosion had yet to be determined.
"There was a powerful explosion that destroyed 30 metres of the pipeline. The line is closed down for now. A fire broke out, but it is no longer burning. There are no casualties and no threat to local residents," Trigub said by telephone.
"You can imagine what 30 metres of destroyed pipeline means."
A spokesman for Ukrainian state energy firm Naftogaz said by telephone that the country's pipeline network was still ensuring agreed levels of supply across its territory.
"There are no changes in volumes of gas being transported," Yuri Korolchuk said. "Volumes due to pass through the damaged section are being redirected through the Soyuz pipeline."
Officials in the Czech Republic, Hungary, Poland and Romania reported normal flows.
"Supplies to Hungary are safe, gas continues to flow, Hungary is unaffected," Economy Ministry spokesman Gergely Abraham said.
Martin Chalupsky, spokesman at dominant Czech gas importer and supplier RWE Transgas, noted no disruptions but said the company would beef up supplies through a northern route bringing Norwegian gas through Germany as of Saturday.
He said there was enough gas in storage facilities following a mild winter to cover "several months" of domestic consumption.
The Slovak natural gas monopoly SPP, which manages the Slovak section of the pipeline transporting around 20 percent of gas consumed in the European Union, said it registered no problems with supplies.
