A major power outage hit Almaty and parts of the surrounding region on Friday after three 500 kV transmission lines shut down, triggering automatic protection systems across Kazakhstan’s electricity network.

Axar.az reports, citing The Times of Central Asia, that Alatau Zharyq Company said the outage began at 2:38 p.m. after lines L-5400, L-5300 and L-5320, operated by national grid company KEGOC, unexpectedly went offline. The shutdown caused electricity supplies to be cut to consumers in Almaty and Almaty Region.

Blackouts were also reported in Bishkek, Kyrgyzstan, and Dushanbe, Tajikistan, although authorities had not confirmed any link between the outages.

The cause of the transmission-line failures remained unclear. The outages also disrupted internet and mobile services in some areas and occurred amid high temperatures across the region.