Russia’s Novatek has said that work at a terminal it controls on the Baltic Sea has been suspended after a fire broke out caused by “external influence.”

On Sunday, a fire broke out at the terminal belonging to Novatek, Russia’s largest liquefied natural gas producer, regional officials said amid reports of explosions and Ukrainian drone sightings in the area.

“According to preliminary information, the fire was the result of external influence,” the company said in a statement, giving no further details.

“The technological process at Novatek-Ust-Luga has been stopped, and an operational headquarters has been established to eliminate the consequences. Damage assessment will be carried out later,” the company said.

The Ust-Luga complex, located on the Gulf of Finland about 170 kilometres (110 miles) west of St. Petersburg, processes stable gas condensate into light and heavy naphtha, jet fuel, fuel oil and gasoil, according to Novatek’s website.

The port is used to ship processed products to international markets.

“No casualties as a result of a fire at Novatek’s terminal in the port of Ust-Luga. Personnel were evacuated,” Aleksandr Drozdenko, governor of Leningrad Oblast, posted on Telegram along with a short video showing a massive fire and smoke at a chemical complex.

“A high alert regime has been introduced in the Kingiseppsky district (which includes the port),” he said, noting that the blaze was “localised”.

Russia’s Defence Ministry announced Sunday that Ukrainian attacks overnight had been foiled but made no mention of any incident in the Leningrad region.