Millions of people are left without power after a huge blackout hit three Central Asian countries - Kazakhstan, Uzbekistan and Kyrgyzstan - after a major power line was disconnected in Kazakhstan, according to authorities and residents.

The capitals of Kyrgyzstan and Uzbekistan as well as Kazakhstan’s economic hub Almaty suffered power cuts at around lunchtime on Tuesday, with media and officials reporting that the blackouts had extended far into the provinces of the three countries.

The grids of the three ex-Soviet republics are interconnected and linked – via Kazakhstan - to the Russian power grid which they can use to cover unexpected shortages.

But Kazakhstan’s North-South power line, which links densely populated southern Kazakhstan and its two neighbours to major power stations in northern Kazakhstan and the Russian network, was disconnected on Tuesday morning due to “emergency imbalances” in the Central Asian part of the grid, KEGOS, Kazakhstan’s national electricity provider, said.

Restarting power plants

Authorities in Uzbekistan and Kyrgyzstan said they were restarting power plants after emergency shutdowns and would initially remain disconnected from the Central Asian grid.

Uzbekistan’s energy ministry said in a statement on its official Telegram channel that the power outage had been triggered by an accident in Kazakhstan’s power grid.

“As a result of a major accident in the power grids of the Republic of Kazakhstan, there was a power outage in the (southern Kazakh) cities of Almaty, Shymkent, Taras, Turkestan (regions) and adjacent areas,” the statement said.

“The Uzbek power grid, which is connected to the Unified Power Grid, was damaged as a result of an accident that led to sudden changes in voltage and frequency on 530 lines from Kazakhstan,” it added.

A spokesman for Kyrgyzstan’s energy ministry told AFP by telephone that power had failed “due to an accident in the regional energy grid”.

Russian news agency RIA Novosti reported that the airport in Almaty, where the power cut did not affect the whole city, was continuing to work normally, but that Tashkent’s airport had stopped receiving flights due to the power outage.

Tashkent’s metro, the largest in the region, had also ceased working, an AFP correspondent noted, adding that tap water was barely running.

Bishkek’s airport was working at reduced capacity, local website 24.kg reported, citing the airport’s management.

‘Crypto power use’

Central Asian countries have seen their grids burdened by a summer drought that affected hydropower capacity in Kyrgyzstan and by a boom in cryptocurrency mining in the region, especially in Kazakhstan.

The growth of cryptocurrency mining in Kazakhstan was linked in part to a de facto ban on the practice in next-door China, and a spike in prices for volatile cryptocurrencies such as Bitcoin in the second half of last year.

Southern Kazakhstan, which traditionally endures energy deficits and relies on supplies from the electricity-rich north of the country, was especially affected by the influx.