Berlin police have arrested six people who they suspect were planning a city-endangering, violent attack.

The suspects, aged between age 18 and 21, were believed to have been preparing a knife attack against the city’s Sunday half marathon, and had been linked to a Tunisian Islamist who killed 12 people in a truck attack in December, 2016.

Several addresses and devices have been seized and searched and Berlin Mayor Michael Mueller thanked the city’s protection forces for preventing such an attack with their “vigilance and police work”.