Suffolk Fire and Rescue is investigating the cause of nine “spot” fires that took place along Interstate 664 northbound Monday afternoon.

The fires were reported at 2:22 p.m. Firefighters responding to the calls found the nine fires that burned a total of less than half an acre, according to a city press release.

The Chesapeake Fire Department provided mutual aid based on the location, according to the press release. There were no injuries.

The cause remains under investigation.