A fire broke out Thursday on Russia’s only aircraft carrier as it underwent repairs in a shipyard in the country’s northwest, Russian news agencies reported, with at least one worker reported missing.

Two people who had been missing in the fire have been found alive while six others were rescued, Russian state news service Interfax reported on December 12. One person remains missing.

Three people were undergoing treatment for injuries, Tass reported.

The Admiral Kuznetsov had been undergoing repairs at the Zvezdochka shipyard in Murmansk. It suffered previous damage in October 2018 when a crane crashed onto its deck.

More than 400 people were on board when the fire erupted, Tass quoted a Zvezdochka spokesman as saying.

The Admiral Kuznetsov – launched in 1985 and the flagship of the Russian navy – has been undergoing its first major repairs since 1997.

The repairs were expected to be completed by the end of 2020, with the warship rejoining the navy in 2021.

With reporting from AFP