Provincial governor spokesman Omar Zwak said the incident took place in Nawzad district after a suicide bomber detonated a vehicle-borne improvised explosive device (VBIED) near a police check post.
Zwak further added that the victims were all members of the Afghan National Police Public Order forces.
He said a truck packed with explosives was used to carry out the suicide attack on the check post in Anzur Shali area.
The Taliban militants group claimed responsibility behind the attack.
Helmand is among the volatile provinces in southern Afghanistan where anti-government armed militants are actively operating in its various districts and frequently carry out insurgency activities.