Fourteen staff members were injured after a fire broke out at Rikers Island Thursday evening, authorities said.

Someone apparently set a mattress on fire in a holding area for women at the jail, causing heavy smoke to spread through the area about 5:45 p.m.

All 14 patients were treated for smoke inhalation at local hospitals, and authorities said several of the patients were in serious but stable condition, while the others were treated for minor smoke-related injuries.

The cause of the mattress fire is under investigation, authorities said.