On April 28, Spanish grid operator Red Electrica said on Monday that power supply had been partially restored following a nationwide blackout earlier today. "Power has now been restored to substations in several areas in the north, south and west of the peninsula, and work is underway to restore power to the whole country," the operator announced in a statement. The blackout also affected neighbouring Portugal, causing traffic problems in Lisbon. "The collapse of Spain's grid has raised fears of potential cyber attacks, but the European Union said there was no evidence of sabotage.