MANILA (2nd UPDATE) - Several power plants bogged down on Tuesday night, causing power interruptions in parts of Metro Manila, the country's largest electric distribution firm said.

About 1,400 to 1,600 megawatts of power were shaved off the grid after "sudden plant outages" in Sta. Rita, San Gabriel, San Lorenzo and QPPL in Batangas at 7:30 p.m., Manila Electric Company (Meralco) said.

“Based on the information we have, there are several plants that went offline kaya mayroon tayong deficiency sa Meralco franchise areas,” Joe Zaldarriaga, Meralco's spokesperson, told dzMM.

Meralco is coordinating with the National Grid Corporation of the Philippines to determine the cause of the plant outage, he added.

Zaldarriaga said before the brownout, Meralco was distributing 5,300 megawatts to meet demand of its customers.

“’Yung kakapusan natin, more than 20 percent,” Zaldarriaga said.

The brownouts were not metro-wide, but covered large parts of Meralco's franchise area, he said.

Among the areas that lost power on Tuesday night were Rizal, Bulacan, Laguna, Quezon, and parts of Metro Manila.

According to First Gen Corp., their Santa Rita, San Lorenzo and San Gabriel power plants went down at around 7:31 p.m.

"We understand there was at least another plant that also went down. The cause of the incident is still under investigation," First Gen said.

According to the company, Avion already has two units running after it was dispatched by NGCP around 8 p.m. Start-up of Santa Rita and San Lorenzo units is ongoing.

NGCP said the power supply went back to normal as of 8:50 p.m.

Investigation is ongoing as to the cause of the power outage in several plants in Luzon.