Portugal is supplying electricity to clients from its own sources as power exchanges with Spain remain suspended amid an inquiry into the causes of a blackout earlier this week, the energy minister said on Friday.

Electricity is pulsing through Spain and Portugal again after a massive outage knocked out power in both countries on Monday. So too are questions.

Spain's investigation into the power outage that blacked out the entire Iberian Peninsula this week continued Thursday as top security officials met Wednesday.