PHOENIX -- Nearly 3,000 Arizona Public Service utility customers in Scottsdale are in the dark due to a power outage, an APS spokesman said.

The boundaries are Pima Road/Loop 101 to the west, Greenway Road to the north, 100th Street to the east and Sweetwater Avenue to the south, APS spokesman Damon Gross said. The power outage affects about 2,900 customers.

The blackout's cause and when power will be restored are both unknown, Gross said.

Traffic signals on Raintree Drive between 94th Street and Loop 101 in Scottsdale are also out, according to a representative of the city's Traffic Management Center.

Spokesman Dan Edwards said Scottsdale police officers are directing traffic in the area.

Drivers should use caution and treat dark traffic signals as four-way stops, he said.