KIEV, Jan. 31 (Xinhua) -- A technological failure has caused widespread power outages across Ukraine on Saturday, said Ukrainian authorities.

Energy Minister Denys Shmyhal said on Telegram that the incident occurred at 10:42 a.m. local time (0842 GMT) and involved a simultaneous disconnection of the power lines linking the Romanian and Moldovan power systems, as well as the line between the western and central parts of Ukraine.

The failure triggered a cascading outage in Ukraine's power grid and the activation of automatic protection systems at substations, Shmyhal said.

Nuclear power plant units were unloaded, and emergency power outages have been imposed in several regions of Ukraine, he said.

In the capital of Kiev, metro services were suspended due to low voltage, said Mayor Vitali Klitschko.

President Volodymyr Zelensky said all necessary response measures in Ukraine's energy system have been put in place while restoration efforts are underway. ■