Ukraine's power grid has experienced mass outages after a "technical malfunction" caused electrical lines between Moldova, Romania and Ukraine to fail, Ukraine's energy minister said.
The outages knocked out water supplies to Ukraine's capital, Kyiv, and prompted a complete shutdown of the city's metro network, paralysing transport for thousands.
"Today at 10:42 am (0842 GMT), a technical malfunction occurred, causing a simultaneous shutdown of the 400-kilovolt line between the power grids of Romania and Moldova and the 750-kilovolt line between western and central Ukraine," energy minister Denys Shmygal said on Telegram.
"Power will be restored within the next few hours," he added.
President Volodymyr Zelensky called the incident an "emergency" and said restoration work was under way.
"The task is to stabilise the situation soon," he said on Telegram.
The issue piles further pressure on Ukraine's energy grid, which was already in a fragile state due to weeks of intense Russian bombardment.
Russia has targeted Ukrainian energy infrastructure throughout its nearly four-year invasion but Kyiv says this winter has been the toughest yet, with attacks cutting power and heating to millions during sub-zero temperatures.
Kyiv's metro system completely suspended operations on Saturday due to the power cut.
Around 800,000 passengers use the network daily, according to data published last year.
Residents also use its 52 stations as bomb shelters during Russian attacks.
The metro network will serve as a shelter until power resumes, Kyiv mayor Vitali Klitschko said in a post on Telegram.
