An explosion occurred at a natural gas export terminal near the Russian city of St. Petersburg on Sunday, officials said.

The explosion caused a large fire, according to state news agency Ria Novosti which reported that the fire had been contained and there were no reports of injuries.

The cause of the fire is not known, but local media reported that drones had been seen in the area.

Ukraine usually does not admit such attacks. But Ukrainian media cite sources who say Kiev is behind it.

Both Russia and Ukraine have used drones during the war.

Russia began its full-scale invasion of Ukraine nearly two years ago, but has made little progress in recent months.

On Sunday, 25 people were killed and 20 wounded in shelling in the Russian-controlled city of Donetsk in eastern Ukraine, said Alexei Kulemzin, the city’s Russian-established mayor. Kiev also did not comment on this attack.

Regarding Sunday’s explosion near St. Petersburg, regional governor Alexander Drozdenko said a “state of high alert” was in place after the incident at gas producer Novatek’s terminal in Ust-Luga on the Gulf of Finland.

The Russian company announced today that work at the gas terminal it manages in the Baltic has been suspended following the incident.

“According to preliminary information, the fire was the result of an external impact,” the company said in a statement, without giving further details.

“The technological process at Novatek Ust-Luga has been stopped, and an operational headquarters has been established in order to minimize the consequences. Damages will be assessed later,” the company said.