An interim report by Emirati investigators into last year's crash of a United Parcel Service plane in Dubai indicates they remain focused on the role played by lithium batteries in causing an onboard fire.
The report stops short of saying what sparked the blaze.
The United Arab Emirates' General Civil Aviation Authority says investigators are examining "several possible ignition sources, primarily the location ... of lithium and lithium derivative batteries" on the Boeing 747-400.
The GCAA provided a copy of the report on Thursday, but says it was issued last month.
The jet crashed on Sept. 3, 2010, after the cockpit filled with smoke. Both pilots were killed.
A final report is expected next year.