Germany hunts suspect as IS claims attack

Assault comes at a sensitive time for Merkel who is running for a fourth term in 2017

German police on Wednesday stepped up their hunt for the driver of a truck that plowed through a Berlin Christmas market, in a deadly assault claimed by the Islamic State group.

Police initially arrested a 23-year-old Pakistani asylum seeker, who was released late on Tuesday for lack of evidence, prompting fears of a killer on the loose and further rattling nerves in a shocked country.