Millions of people in Spain, Portugal and parts of southern France lost power on Monday following a "severe disruption" in the European electrical system, the Spanish prime minister said. The cause of the disruption is still unknown,

Play was halted at the Madrid Open tennis tournament, while the Spanish capital's metro system ground to a stop.

Spain, Portugal and parts of France were plunged into chaos after power outages grounded flights, stopped trains and left whole cities without electricity or phone signal.