Cuban authorities said they had begun restoring power to the eastern half of the island on Thursday, a day after Hurricane Rafael knocked out the country's electrical grid, leaving 10 million people in the dark.

The hurricane center cautioned there is "larger-than-normal uncertainty regarding Rafael's intensity later in the forecast period."

Hurricane Rafael blew through western Cuba on Wednesday night, flooding streets, damaging buildings and plunging millions of people into darkness. The country’s national power company said strong winds had caused the blackout.