A fourth person died Friday from wounds suffered in an attack on the Christmas market in Strasbourg, as investigators worked to establish whether the main suspect had help while on the run.

The man who opened fire on a Christmas market in Strasbourg, France was killed on Thursday after a shootout with police.

The death toll in an attack on Strasbourg's Christmas market rose to three on Thursday as police searched through eastern France and manned checkpoints on the German border in a hunt for the suspect.