A gas pipeline connecting Lithuania and Latvia was hit by an explosion on Friday but there was no immediate evidence of an attack, Lithuania gas transmission operator Amber Grid said.
Video published by Lithuania's public broadcaster LRT showed a fire raging at the blast site in the Panevezys county in northern Lithuania. The fire was put out, the Lithuania pipeline grid operator's chief executive said.
"According to the initial assessment, we do not see any malign cause, but the investigation will cover all possible options," Amber Grid Chief Executive Nemunas Biknius told a news conference.
The supply of gas was cut off but the CEO said the blast had damaged one of two parallel pipelines sending gas from Lithuania to Latvia and that Amber planned to restore supply by using the unaffected one.
"We plan to restore the gas supply in a few hours, in comparable amounts. We plan that the clients will not feel an impact from this event", Biknius told reporters.
Lithuania, like war-torn Ukraine, borders Russia and is situated on the Baltic Sea where the Russia-to-Germany Nord Stream gas pipelines were destroyed by explosions last year.
Flames initially rose some 50 metres (160 feet) in the air and could be seen at a distance of at least 17 km (11 miles), LRT reported.
There were no injuries or fatalities reported, Baltic news agency BNS said.
Povilas Balciunas, the head of public administration in the nearby town of Pasvalys, told Reuters flames initially burned like "a big torch of gas" before calming down.