Seven people were in hospital, with one in a serious condition, after a fire at Russia's Omsk oil refinery, the local governor said on Monday, although the plant said it was operating as normal and production plans would not be affected, Paralel.Az reports citing Reuters.

"The fire at the Omsk refinery is under control. The plant's automatic safety system detected a fire in technological equipment ... The company is operating as usual," the refinery - Russia's largest - said in a statement.

Vitaly Khotsenko, the local governor, said on the Telegram messaging app that seven people were hospitalised, with one of them in a serious condition.

The plant, controlled by Gazprom Neft, said the fire would not affect its production plan, which it would be able to deliver thanks to additional production capacity.

The cause of the fire was not immediately clear. Several Russian oil refineries have been targeted by Ukrainian drone attacks.

The Omsk refinery processed more than 21 million metric tons (420,000 barrels per day) of crude oil in 2022.