(CBS News) Sebastien Barthe, a spokesman for the French agency, told The Associated Press in Paris that the plane's automatic detection system sent messages indicating smoke a few minutes before the plane disappeared from radar while flying over the east Mediterranean early on Thursday morning.
The messages, he explained, "generally mean the start of a fire," but he added: "We are drawing no conclusions from this. Everything else is pure conjecture."
Barthe's disclosure of smoke detection aboard the flight followed a report by an industry publication that sensors detected smoke in a lavatory, suggesting a fire started onboard before the aircraft went down.
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The publication cited information transmitted through the plane's Aircraft Communications Addressing and Reporting System, or ACARS, which transmits data from the plane to the ground in the form of a series of messages. Those messages showed that smoke was detected in the plane's lavatory near the cockpit, according to the report.