Thousands of people in Hawaii have been told to evacuate their homes as the US state suffered its worst flooding in decades.

It is the second severe storm to hit the archipelago in the last week, causing damage that could exceed $1 billion (£745m), according to Honolulu Mayor Rick Blangiardi.

More than 230 people have been rescued so far, Blangiardi told a news conference on Friday. Heavy rains continued to fall on the archipelago in the early hours of Saturday morning.

The authorities warned that a dam in Oahu, the state's most populous island, was at risk of collapse. Blangiardi urged residents to "stay safe" and "take the storm as seriously as you can".

Speaking at the news conference on Friday, Governor Josh Green said there had been no reported fatalities in the storms, and praised the emergency workers working to keep people safe.