A major power blackout hit Montenegro, Bosnia, Albania and most of Croatia’s Adriatic coast on Friday, officials said, disrupting businesses, shutting down traffic lights and leaving people sweltering in the middle of a heatwave.

Power operators in the four countries said they were investigating what caused the failure. Albania’s Top Channel TV cited unnamed sources saying an interconnector had failed in Montenegro, though there was no official confirmation.

In Bosnia, there was no power in the capital Sarajevo and the cities of Banja Luka and Mostar, Reuters reporters said. Local media reported a blackout across the country.

Traffic ground to a halt in the Croatian coastal city of Split after traffic lights failed, state TV HRT reported. Ambulance sirens rang out cross the city, it added.

Croatia’s HEP power utility said that the outage in parts of the country had been caused by “an international disturbance that affected several countries,” without going into further detail.

“The Croatian transmission system operator is conducting an analysis with the system operators of neighbouring countries to determine the cause,” HEP added.

The utility said it had put its production capacities into full operation to ensure “supply in the shortest possible time”.

Montenegro power distributor CEDIS said “network outages” had cut power over most of the country.

Ivan Asanovic, the executive director of Montenegro’s CGES power utility, said the cause of the blackout “of regional magnitude” was unknown and that CGES and CEDIS were working together to resolve it.

Albania’s Top Channel said the capital Tirana and a number of towns had no electricity.

Source: Reuters