BARCELONA, Spain — A fire at a chemical factory in northeastern Spain forced emergency services to issue health warnings to 150,000 local residents and stay-indoors orders for five nearby towns, authorities said Saturday.

Health services said that medics attended to four people who had reported breathing problems.

The fire broke out early on Saturday inside a warehouse at the plant near the town of Vilanova i la Geltrú. The warehouse housed 70 tons of chlorine for use in swimming pools, firefighters said.

The stay-indoors order stayed in effect for seven hours for the nearest municipalities in the area between Barcelona and Tarragona on the Mediterranean coast.

Firefighters said that by Saturday afternoon that the fire was under control.