Gas supplies from the Central Asia country of Turkmenistan to Russia have been halted by a pipeline explosion.
No cause was given for the blast but the Russian state-owned energy company, Gazprom, said the incident would not affect supplies to its customers.
Gazprom said alternative supply routes to Russia were being explored.
Turkmenistan is a major gas supplier to Russia - most of which is then sold on by Moscow to EU countries. It is also the biggest producer in Central Asia.
In a statement, Gazprom said it had been informed of the blast, along the Davletbat-Daryalik pipeline, in the early hours of Thursday.
"Since then, transport of Turkmen gas to Russia has not been carried out," Gazprom said, adding that the Turkmen side was working to rapidly repair the damage.
A Turkmenistan government official confirmed the blast and said that repairs to the damaged section would take several days.
Turkmenistan's massive gas reserves are effectively controlled by Moscow, since it relies on Russian energy giant Gazprom's Soviet-era pipelines for distribution.
But the BBC's Central Asia correspondent, Rayhan Demytrie, says Turkmenistan is looking for ways to diversify its energy sector.
A major pipeline for the delivery of Turkmen gas to China is currently under construction.
Turkmen gas could also become the key to the success of the Nabucco pipeline, an EU-backed project designed to provide an alternative to Russian gas supplies to Europe.