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A large blast has hit a gas pipeline in the Pasvalys region of northern Lithuania, near the Latvian border.
Images broadcast by local media showed flames illuminating the night sky, but officials say there have been no injuries caused by the explosion.
Latvia's Defence Minster Artis Pabriks wrote on Twitter that the cause of the incident would be investigated, but said sabotage could not be ruled out.
But the pipeline's operator said it did not believe the blast was suspicious.
"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 reporters. "We do not see the signs of any potential impact from outside."
Mr Biknius said the pipeline - which was built in 1978 - had undergone some recent maintenance work, and that officials would try to establish whether that had contributed to the blast.
"All reasons will be investigated and clarified in the coming days," Mr Biknius said.
He added that the gas supply to the pipeline had been cut off and that he expected the fire to subside in the coming hours. Amber Grid added that the blast had taken place "away from any residential buildings".
The pipeline consists of two parallel system, and Amber Grid said the explosion occurred in one of them. The other was undamaged.
The mayor of Pasvalys district, Gintautas Geguzinskas, told LRT that he didn't have any concrete information on the cause of the blast, but said that local residents had told him "they saw some work being done near the pipeline where the explosion happened".
In footage obtained by the LRT news outlet, flames could be seen rising some 50 metres (160 feet) into the air. The blast was also reportedly visible from up to 17 km (11 miles) away.
Meanwhile, the BNS news agency reported that officials had decided to evacuate the nearby village of Valakelie. The town has a population of around 700 people.
Firefighters extinguished the flames around 21:00 local time (19:00 GMT).
But Povilas Balciunas, the head of public administration in the nearby town of Pasvalys, told the Reuters new agency that flames blazed for almost four hours after the initial explosion.
The pipeline is used by Amber Grid - Lithuania's national gas company - to transfer gas into the north of the country and to supply neighbouring Latvia.
Consumers in the area are being supplied by an alternate pipeline.