LONDON (AP) — Two people have been hospitalized after a fire broke out at the shipyard that builds Britain’s nuclear-powered submarines, but there is “no nuclear risk,” police said Wednesday.

Cumbria Constabulary said a “significant” fire broke out soon after midnight at the BAE Systems shipyard in Barrow-in-Furness, northwest England.

Video shared on social media overnight showed flames shooting out from the Devonshire Dock Hall building while alarms blared.

“When I opened the front door, we just saw a lot of black smoke,” said Donna Butler, who lives next to the shipyard. “It was a lot of black smoke, like really thick black smoke, and it was very loud.”

The force said two people were taken to hospitals with suspected smoke inhalation and there were no other casualties. It advised people living nearby to stay indoors and keep doors and windows closed.

The 150-year-old shipyard, about 220 miles (350 kilometers) northwest of London, is currently building several nuclear-powered submarines for the Royal Navy. It is also where the four subs that carry the U.K.’s nuclear missiles were constructed, and where replacements for those vessels, due to enter service in the 2030s, are being constructed.