It shall be unlawful for any driver or operator of a motor vehicle who, having been given a visual or audible signal by a police officer directing the driver or operator to bring his vehicle to a stop, willfully fails or refuses to obey that direction, increases his speed, extinguishes his lights, or otherwise flees or attempts to elude the officer. The signal given by the police officer may be by hand, voice, siren, or a red or blue light. However, the officer giving the signal shall be in police uniform and, if driving a vehicle, the vehicle shall be marked showing it to be an official police vehicle.