A fire last week at an Oak Bluffs junkyard remains under investigation and is being considered suspicious, a fire official said Wednesday. 

Around 9 p.m. Dec. 27, a large fire at the JWL Transport junkyard off County Road and Pennsylvania avenue burned through three buses, several cars, trailers and other debris. A witness reported a large explosion and flames billowing from the property. The fire department believes the fire started in cars near the front of the buses. 

How the fire started remains unclear, but in an interview with the Gazette this week, fire Chief Nelson Wirtz confirmed that both the fire department and town police department continue to probe the cause.

“It is suspicious,” he said of the fire. “That is why there is still a very active investigation.” 

Firefighters are trained to observe potential starting points and causes of fires as they respond and afterwards when the fire is put out, Mr. Wirtz said. But because of the scale and destruction caused by the JWL fire, there are few clues. 

“The scene at JWL was so compromised by the time our firefighting efforts were done,” Mr. Wirtz said. “We had dumped thousands of gallons of water....Any evidence is difficult to ascertain.” 

Police chief Jonathan Searle also confirmed the fire was being considered suspicious but declined to comment on the ongoing investigation.