AbujaEdo, Oyo, Osun and Rivers approved the state police amendment.
Nigeria has 380,000 police for 200 million people, one per 650, the presidential working group says.
The amendment needs 24 of 36 assemblies, and only creates the constitutional basis for state forces.
Nnadubem Moghalu, the group’s secretary, concedes governors could use state police against political rivals, or local majorities against minorities.
20 more must approve, and the National Policing Bill that would build the forces is still being drafted.
Sources: Premium Times Nigeria