Police said the incident took place shortly after 8 a.m. today. The 26-year-old suspect, who wasn't identified, spoke to the officer in his patrol car then grabbed his clothes and tried to drag him out of the vehicle.
The officer used pepper spray to deter the assailant, injuring him slightly. Police say the officer was unhurt.
The incident comes after an attack Sunday night on an Austrian soldier who was guarding the Iranian ambassador's residence in the Austrian capital. The attacker in that case, an Austrian national, was fatally shot.