Berlin police have arrested six people who they suspect of « preparing a grave city-endangering violent act ».

The arrests, of people aged between 18 and 21, came amid German media reports of a knife attack being foiled against Sunday’s half-marathon in the city.

A police spokesman said on Sunday there was no conclusive evidence the run had been the target of the alleged plot. Police say a number of searches have been made, with some electronics seized for further examination.

Berlin Mayor Michael Mueller thanked the city’s security forces for preventing an « impending attack with their vigilance and police work ».

Die Welt newspaper earlier reported that one man detained had planned to mount a deadly knife attack on participants and spectators at the half-marathon. The newspaper reported that those arrested were suspected of having links to a Tunisian Islamist who killed 12 people in the city in a December 2016 truck attack.

Sunday’s police statement said that several addresses had been searched along with two vehicles. The police declined to give further details.