UPDATE: State Forest Fire Service Investigating Riverdale Fire

The New Jersey Forest Fire Service is investigating a brush fire that broke out at about 5 p.m. Thursday in Riverdale, according to the Suburban Trends.

The Trends reported Friday that Spokesman Larry Hajna said the agency has not yet determined the cause of the fire but that it is under investigation. A police officer on the scene Thursday told Tri-Boro Patch  playing around in the woods.

Sgt. James MacIntosh of the Riverdale Police Department said Friday the teenage males, whose names were not released and are between the ages of 13 and 15, admitted to police that they were playing with matches when the fire started. The juveniles have not yet been charged but they will be pending the investigation, MacIntosh said, though he could not confirm the exact charges at this time.

MacIntosh said about 5.5 acres of forest burned, mostly brush, in the fire that lasted until 9 p.m. The state Department of Transportation assisted in shutting down one lane of Route 23 traffic as crews worked to put out the fire on the mountain.

Multiple fire departments, including the . and , police officers and first aid responders arrived at the scene to assist as the flames spread and made their way toward Route 23 in the early evening hours.

MacIntosh said a firefighter complained of shortness of breath resulting from the incident and was sent to The Valley Hospital in Ridgewood but that the firefighter is now doing fine. No other injuries were reported as a result of the fire and no property damage was reported, he said.