A government official said the latest fire, which caused blackouts in large parts of the southern city of Aden, was caused by a surge in voltage at a major power generation facility which resulted in an explosion. The official said the fire had been extinguished.
Earlier this week the government said southern secessionists had blown up a power station in the southern Al Dali province.
It also blamed secessionists for another power station fire in Hadramout and arrested ten engineers on suspicion of involvement. No secessionist group has claimed responsibility for any of the incidents.
Clashes between the government and separatists in the south have intensified in recent months, two decades after the unification of Yemen's north and south.
Police shot dead two protesters in Aden on Wednesday in a clash during a "Day of Rage" called by secessionists. [ID:nLDE6661KC]
Yemen, which neighbors oil exporter Saudi Arabia, is also fighting a resurgent Yemen-based Al-Qaeda arm that caught the world's attention when it claimed responsibility for a failed attempt to bomb a US-bound plane in December.
Tension has been high in Aden, the capital of South Yemen before unification, since authorities launched door-to-door raids on June 25 for Al-Qaeda militants wanted over an attack on the city's intelligence headquarters that killed 11 people.
