Manila: Armed men bombed six high-voltage power pylons in rebel-infested areas in the southern Philippines, cutting off electricity in large parts of Mindanao island, officials said on Friday.

Miguel Dominguez, governor of Saranggani province, said it would take four days for engineers to restore electricity service fully in the area, including portions of General Santos. Police believe rebels fighting for a separate homeland in the south were responsible for the attacks, but a power company said criminal groups may also be involved.

Four transmission towers were toppled in the Lanao provinces on Friday with improvised bombs planted at the base of the steel structures.

Spokesperson for Lanao's Transco, Elizabeth Ladaga, said the company's services had been disrupted due to the attacks and added that Mindanao's eastern and southern portions were affected. Ladaga said the company had lost about 20 steel towers since the start of the year due to sabotage blamed on criminal groups attempting to extort money from them.