Hours after a massive power cut hit large parts of Spain and Portugal, Spanish PM Pedro Sánchez says the cause is still being investigated

Spain and Portugal are reeling from a massive, unexplained power outage that knocked out traffic lights, caused chaos on roads and in airports, and prompted both countries to declare a state of emergency.

Spain's Interior Ministry on Monday declared a state of emergency after a nationwide power blackout hit most of the Iberian Peninsula.The ministry added the emergency status will be applied in the regions that request it.