A fire and explosions at a substation in southern Iraq briefly led to a complete power grid shutdown on Saturday, and caused longer-term disturbances to supply in central and southern parts of the country. 

The outage comes amid peak summer demand, with scorching temperatures across most of the country. Weather forecasts expect peak temperatures near 50 degrees Celsius (122 degrees Fahrenheit) consistently in the coming days. 

It also took place on the Shiite religious holiday of Ashoura amid many public gatherings. 

Electricity is a sensitive issue in Iraq — a country with vast oil reserves but a dilapidated power grid incapable of meeting peak demand.

Outages lasting hours are commonplace every summer. 

Protests about the patchy supply are by no means unheard of — the most recent took place this month. 

What happened and where? 

A fire broke out at the Al-Bkir substation in Basra and resulted in the separation of transmission lines linking southern and central regions, leading to a complete shutdown of the electrical system in the area, Iraq's Ministry of Electricity said in a statement. It said the fire was accidental. 

"The power grid experienced a total shutdown on Saturday at 12:40 p.m. (0940 GMT/UTC) due to a fire that affected a transmission substation in Basra province," the ministry said. 

Ministry spokesman Ahmed Moussa told the AFP news agency that at some point the incident affected main supply to "all of Iraq." 

"Speedy repairs are under way ... to gradually restart the power plants and transmission lines," the ministry said. 

Iraq can't meet peak summer demand in searing heat

Rolling power cuts hit Iraq each summer and can last up to 10 hours a day. 

Many households subscribe to neighborhood generators for emergency supply, if they can afford it.

But the generators often don't provide sufficient power to operate high-energy equipment like air conditioning units, highly sought after in temperatures nearing 50 degrees Celsius. 

Peak summer demand reaches more than 32,000 megawatts a day in Iraq. The country is trying to expand its capacity, and according to the electricity ministry, this year it reached a new high of 26,000 megawatts a day. 

msh/sri (AFP, AP)