Police in the Bono Region have arrested a 48-year-man for allegedly killing his grandparents with a mattock.

The man, identified as Frederickson Ericson, is said to have butchered his grandparents whilst they were asleep.

The two deceased persons have also been identified as J.K Amoah, 90, and Nana Adjoa, 85.

The incident happened at New Town Extension in Sunyani.

Mr. Ericson is believed to be mentally unstable and an alcoholic.

Speaking to the media, Public Relations Officer at the Bono Police Regional Command, ASP Augustine Kingsley Oppong, said investigation into the matter has commenced.

“Preliminary investigations indicate that Ericson is a mentally deranged person so we’re basing upon that to establish the truth or otherwise of the case,” ASP Oppong said.

ASP Oppong also admonished the public to be wary of persons who are on treatment for mental disorders.

"There are some people who seem to be mentally deranged and are on drugs. You have to be very careful and take good care of them," he warned.

The bodies of the deceased have been deposited at the morgue for autopsy.