The Massachusetts Port Authority's fire chief, Bob Donahue, said the fire began in an auxiliary battery pack that supplies the plane with power when the engines are shut down. Fire crews using infrared equipment found flames in a small compartment in the plane's belly and quickly brought the fire under control, he said.
"Something caused this battery pack to overheat, ignite," Donahue said, adding it's too soon to know the cause.
The flight landed normally at about 10:15 a.m. Its 173 passengers and 11 crew members had already gotten off the jet when a mechanic spotted light smoke about 15 minutes later and notified Massport.
"When we arrived, it was a heavy smoke, and that was in three minutes, so this was advancing," Donahue said.
The mechanic was the only person in the cabin when the fire broke out. One firefighter had skin irritation after contact with the chemical used to douse the fire, Donahue said.
The 787 is Boeing's newest plane, and the first one was delivered in late 2011. In November 2010, a test flight had to make an emergency landing after an in-flight electrical fire. The fire delayed flight tests for several weeks while Boeing investigated.
Last month, a United Airlines 787 flying from Houston to Newark, N.J., diverted to New Orleans because of a mechanical issue. No one was injured.
Ed Freni, Massport's aviation director, said JAL officials reported that the plane that caught fire was delivered to the airline in late December.
Eric Weiss, a spokesman for the National Transportation Safety Board, said the agency is sending several investigators to Boston on Monday to look at the airplane. The Federal Aviation Administration also said it was investigating.
Boeing Co. spokeswoman Lori Gunter said the company was aware of the fire and was working with JAL. She said she couldn't immediately answer other questions because Boeing's technical team was focused on the investigation.
JAL began nonstop service between Boston and Tokyo's Narita Airport using the new Boeing 787 in April. A return flight to Tokyo was cancelled Monday and JAL is working to reschedule passengers, a JAL spokeswoman said.
Associated Press writers Joshua Freed and Denise Lavoie contributed to this report.