The National System Operator (NSO) says the electricity supply has been restored to around 50% of the areas affected by the islandwide power outage since this morning (17).

Earlier, the NSO said power restoration has been progressing area by area since noon, and that it hopes to fully restore the national grid by around 6.30 p.m. this evening.

According to the NSO, the nationwide outage occurred due to a system instability in the transmission network, resulting in a total failure of the country's power grid. The interruption was reported at around 11.45 a.m.

Electricity supply has already been restored in several areas of the Colombo, Gampaha, Galle and Badulla districts, the NSO said.

The NSO is continuing restoration work and has requested owners of rooftop solar PV systems to disconnect their systems until further instructions from the NSO, in order to support the restoration efforts.

Earlier, Energy Minister Anura Karunathilake said efforts were underway to restore the power system, with electricity expected to be restored in stages as soon as possible. Although the exact cause of the outage had yet to be identified, investigations were focusing on whether an operational failure at a power plant in Kotmale yesterday (16) had contributed to the system imbalance.

Meanwhile, the National Water Supply and Drainage Board (NWS&DB) said water supply from the main pumping stations had returned to normal following the power outage.

However, the Water Board has advised consumers to use water sparingly until further notice.