WASHINGTON — A union leader for a civilian Navy fire department that responded to the Washington Navy Yard shooting says faulty radios hindered emergency communications among some of the responders.

Greg Russell, the union president, said today that the radio malfunctions were described to him by multiple firefighters who responded to Monday’s massacre.

He says that the problems prevented firefighters from communicating with each other and that the department had to send a runner outside to physically transmit messages and commands.

The firefighters were ultimately able to use the radio system of the local fire department. He says the problems caused unnecessary delays, though it was not clear what effect those delays may have had.

A spokesman for Naval District Washington had no immediate comment Friday.