Power supplies to large areas of Java and Bali islands, including the capital Jakarta, were disrupted for several hours on Thursday, state-run electricity company PT Perusahaan Listrik Negara (PLN) said.

"There is quite a big fault in the Java-Bali electricity generating system," Mulyo Adji, PLN's general manager for supply, told reporters in Jakarta after the blackout.

The company is investigating whether the fault was at power plants or in the transmission line, he said.

Electricity supplies failed at about 10:15 a.m. (local time) to offices in Jakarta including the Ministry of Energy and the Stock Exchange. Cities in West and Central Java and parts of East Javaalso had power outages.

Most companies in Jakarta, including the Stock Exchange, can continue operations during electricity blackouts.

"The Stock Exchange has a back-up power system, which automatically starts in case of a power failure," said Yose Rizal, head of the monitoring division at the Jakarta Stock Exchange.

Source: Xinhua