Greece's Organized Crime Directorate is leading an investigation into the deadly collision of two firefighting helicopters near Psatha, drawing on expertise gained from the 2005 Helios Airways crash and other past aviation accidents, authorities said.

The battle against major wildfires in Greece continued for a fourth consecutive day as authorities launched an investigation into the fatal collision of two firefighting helicopters that claimed the lives of both pilots. The crash occurred during an aerial firefighting mission west of Athens.