Trams are immobilized during a major power outage in Prague, Czech Republic, July 4, 2025. CTK/Ptacek Jan via REUTERS
PRAGUE (Reuters) - A major power outage that hit parts of the Czech Republic on Friday, briefly halting underground trains in the capital Prague, was probably the result of a technical outage, with no signs of a cyber or terrorist attack, authorities said.
The incident is likely to add to concerns about the resilience of Europe's power grids and infrastructure after Spain suffered the worst blackout in its history in April and a fire knocked out the power supply to London's Heathrow airport in March.
"Part of the transmission system is without voltage; the event affected also a larger part of transmission system substations," grid operator CEPS said in a statement.
CEPS later said that five out of eight affected substations had resumed operation and the causes of the outage were being investigated.
It affected the Liberec, North-Bohemia, East-Bohemia and Central Bohemia regions, as well as Prague, CEPS said.
Speaking on Czech Television, Interior Minster Vit Rakusan said the authorities had no information to suggest there had been a cyber or terrorist attack.
Czech Transport Minister Martin Kupka said on X trains were halted on a number of lines and five out of 14 regions of the country were affected.
Prague transport company DPP said it had restored operations after underground trains were briefly halted and tram traffic stopped on the right bank of the capital.
Czech media reported a number of people trapped in elevators in parts of Prague and central Bohemia.
E.ON, which operates part of the grid in south and south-eastern Czech Republic, said its supply area was not affected.
Neighbouring Poland's power grid operator also said its systems were unaffected.
(Reporting by Jan Lopatka, Vera Dvorakova, Nina Chestney, writing by Alan Charlish; Editing by Mark Potter and Barbara Lewis)
