A policeman, Constable Atibiya Ayine, has been gunned down by unknown assailants at Spintex Road in Accra.
Police say Ayine was on guard duty at Poly Tank with 10 other private security officials when they were attacked.
The constable was shot dead and his AK-47 rifle stolen while a private security guard was stabbed and had to be rushed to the hospital.
The public relations officer of the Accra Regional Police Command, ASP Effia Tenge, told Accra-based Citi FM that the police had launched a manhunt for the murderers.
ASP Tenge said the murderers were dangerous since they had an Ak-47 in their possession.
She appealed to members of the public to offer any information could lead to their arrest.