A huge power failure strike Pakistan after midnight, plunging big cities into darkness, as officials battled today to restore electricity power in the country tortured by a paralyzing energy crisis.

The nature of fault was unknown exactly but it sinked about 80 percent country into darkness, the fourth massive breakdown of the system within the previous one month. There were divergent statements about the cause for the breakdown. Initially television channels reported that extremists had damaged the Guddu transmission line in the disturbed Baluchistan province's Nasirabad district.