Latest: 'Islamic State' group claims responsibility for Berlin attack

Update 6.15pm: German prosecutors say a man arrested after the truck attack on a Berlin Christmas market has been released because there is insufficient evidence to tie him to the rampage.

Update 7.52pm: The so-called 'Islamic State' group has claimed the Berlin truck attacker is an IS soldier "targeting citizens of the Crusader coalition" .

'IS' said in a statement from its Amaq news agency that the attacker "in Berlin is a soldier of the Islamic State and carried out the attack in response to calls for targeting citizens of the Crusader coalition".