An active safety system (10) for a vehicle comprising: - an external object sensor system (24) arranged on a host vehicle (12), said sensor system (24) being arranged to, within a detecting range (22) of said sensor system (24), sense objects (14 - 20) external to said host vehicle (12) and generate input data relating to said objects (14 - 20), wherein said input data include an object position ((R,È rel )(t)), - a threat indicator (26) which is arranged to assign a threat level (T k (t)) to each external object (k; 14 - 20) detected by the sensor system (24); and a method run in an active safety system.