Five police officers have been shot in the US state of Pennsylvania, with three of them said to be in a grave condition.

A fourth officer shot in Wednesday afternoon’s incident in rural York County is said to be in a critical condition.

The suspect in the shooting is believed to have died from a self-inflicted gunshot wound, sources told the BBC’s US partner CBS.

Pennsylvania Governor Josh Shapiro said he was travelling to the scene in North Codorus Township, about 100 miles (160km) east of Philadelphia.

“I’ve been briefed on the situation involving law enforcement in York County, and am on my way there now,” Shapiro wrote on X.

“We ask those in the area to please follow the directions of local law enforcement,” he added.

The incident happened just after 14:00 local time (19:00 BST). Images from the scene showed a police officer being airlifted out of the scene in a medical helicopter.

The shooting forced a nearby school district in Spring Grove, Pennsylvania – a small town of about 2,500 people – to briefly shelter in place. The district later said the school had not been affected.

Officials said there was no threat to the public.