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.

The sweeping power outage that hit Spain and Portugal this week has raised questions about the electricity grid in a region not normally known for blackouts.

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