The Solomon Islands Peace Monitoring Council has confirmed that four people have been shot dead on Guadalcanal.
The circumstances of the killings are not clear but PMC says the four were travelling in a stolen police vehicle when they were fired upon.
The dead include women and children - another four people were injured and taken to hospital.
The incident follows the killing of a teenage girl in the region two weeks ago and an attack on Red Cross officials last week.
An extended amnesty to return stolen weapons and stolen property expired in May, with many high-powered weapons still in circulation.