WASHINGTON (Reuters) -The National Transportation Safety Board on Wednesday urged the Southeastern Pennsylvania Transportation Authority to immediately move to eliminate fire risks in its fleet of Silverliner IV railcars.

The safety board said the outdated design of the railcars and the agency's maintenance and operating practices "represents an immediate and unacceptable safety risk because of the incidence and severity of electrical fires that can spread to occupied compartments."

The recommendations stem from the NTSB’s investigation into five fires in SEPTA cars since February.

(Reporting by David Shepardson)