A police officer was shot dead in his vehicle after he was ambushed by a group of men in Ladanna‚ Polokowane‚ police said on Friday afternoon.

National police spokesperson brigadier Vishnu Naidoo said Constable Petrus Gerhardus de Lange was monitoring possible drug activity in the area when he was attacked on Thursday night.

"A group of suspects in two cars drove up to the constable's vehicle.

Four men alighted from the vehicles with handguns and opened fire on the policeman‚" Naidoo said.

He said the 30-year-old constable died on his way to hospital.

Naidoo said it was alleged that a truck driver had also sustained a gunshot wound to the hand by a stray bullet.

National police commissioner general Khehla Sitole has activated a 72-hour activation plan to identify and arrest the killers.

So far this financial year‚ 18 officers have been killed on-duty and 24 off-duty.

"We have lost 42 police officers at the hands of criminals since the start of this financial year alone. The number of our police officers being attacked and killed remains at an unacceptable level despite proactive and reactive interventions‚" Sitole said.