The devastation caused by Hurricane Maria on Puerto Rico could mean that the island is left without power for months, officials have warned.

Flash flood warnings have been issued for the entire island, which continues to be lashed by torrential rain. Maria, which is a category three storm, is now ravaging the Dominican Republic and heading in the direction of the Turks and Caicos islands.

Governor Ricardo Rossello said the island had "not experienced an event of this magnitude in our modern history".

He warned that the electricity grid had been so badly damaged in the storm that the island, which has a population of 3.5 million, could be left in the dark for months.

"God is with us; we are stronger than any hurricane," Rossello told Puerto Ricans. "Together we will rise again."

He called on President Donald Trump to declare the island a disaster area as the storm continued to unleash heavy rain and life-threatening winds. The US president, who described Maria as a "monster", has yet to do so – but has made federal emergency aid available.

The storm has caused at least 10 deaths across the Caribbean. In Puerto Rico, one man died after he was struck by the board he had used to protect his windows.

Authorities have urged people to move to "higher ground" as 30 more inches of rain is predicted to land on Saturday (23 September).

Maria is the second devastating hurricane to strike the Caribbean this season. Irma, a category five hurricane, struck the region earlier in September, and killed at least 101 people.

1 of 3