The attack came three days before the first round of France's tense presidential election.

German investigators are searching for the killer or killers involved in the attack on a crowded Christmas market in Berlin after a man arrested soon after the rampage was released due to lack of evidence and the Islamic State group claimed responsibility.

Latest: It has now been confirmed that 20 hostages have been killed during a siege in a cafe in the Bangladesh capital Dhaka.

A knife-wielding attacker has stabbed a senior police officer to death outside his home in a suburb of Paris.