SAN FRANCISCO, June 11 (Xinhua) -- More than 17,000 residents in San Francisco Bay Area experienced power outages Tuesday following an unprecedented heat wave that scorched the region.

It was unknown what caused the cut-off of the power supply for the customers of California utility Pacific Gas & Electric Co. (PG&E), but company officials, quoted by the San Francisco Chronicle, said they have received an "increase in heat-related outages" in the Bay Area, particularly in the East Bay.

In the cities of Berkeley and Oakland alone, about 7,300 PG&E customers went without power despite the dry heat sweeping the Bay Area.

The scorching heat in the Bay Area broke a several decades-old records on Monday as the temperature in San Francisco hit a record 36 degrees Celsius, while the normal temperature in the city on June 10 is about 19 degrees Celsius, officials said.

Weather forecasts recorded a rare high temperature of about 37 degrees Celsius in Oakland, shattering the record of about 33.3 degrees Celsius set in 1994, while Santa Rosa in Northern California witnessed a high of about 38.3 degrees Celsius, which broke a record from 1921.

PG&E on Tuesday urged its customers to conserve electricity and avoid power consumption at peak hours after the California Independent System Operator, which manages the state's power grid, issued a Flex Alert.

The Flex Alert is an urgent call for residents to immediately conserve electricity and shift power demand to off-peak hours to ease strain on the grid.