BUENOS AIRES, Argentina (AP) _ An overnight power outage triggered blackouts across much of the Argentine capital and seven provinces, leaving 2 million people without electricity, utility company officials said Wednesday.

In parts of Buenos Aires and the city's surrounding suburbs, lights flickered back on after two hours late Tuesday. But huge swathes of the country's interior were still without power several hours later, officials with Edesur and Edenor utility companies said.

Authorities are still investigating the cause of the blackout, which occurred at around 7 p.m. amid steaming summertime temperatures.

It was the second major blackout this year. In February, a nearly two-week long outage hit south and central Buenos Aires leaving some nearly 300,000 people without power.

Wednesday's outage stretched from neighborhoods in Buenos Aires to the provinces of Mendoza, Cordoba, La Pampa, Santa Fe, Rio Negro and Neuquen.