Philippine police have found two more bombs planted along Manila highways. A total of eight explosives have been discovered this week. An indigenous rights group is claiming responsibility.
The first bomb was discovered Friday night in a highway overpass in Manila's financial district of Makati. It was constructed with two hand grenades, a timer and a soda can filled with blue powder.
Officials say the device was not rigged to explode and was probably intended to scare people.
A similar bomb was found Saturday morning in one of Manila's suburbs.
A group calling itself the Indigenous People's Federal Army says it planted the bombs and a series of others recently. The IPFA says it wants a federal system of government to allow separate rule for tribal people and Muslims in the mostly-Catholic Philippines.
Manila's police chief says his force is targeting three groups in its investigation, but will probe all possibilities.