Roseau: More than 15 people were killed and 20 others reported missing after Hurricane Maria battered the Caribbean island of Dominica with winds of 260 kph.

"So far, we would have buried in excess of 15 people," Prime Minister Roosevelt Skerrit announced on Thursday night.

"If there (are) no other fatalities, it is a miracle."

The Category 5 storm made landfall on Monday, flattening homes and destroying vital infrastructure across Dominica, a nation of roughly 72,000 residents that lies near the French overseas territories of Guadeloupe and Martinique.

The UK has dispatched aid to Dominica, which is a member of the Commonwealth.

"It has been brutal. I saw almost complete devastation," Skerrit said, recounting his impressions after making several flights over the territory.

"We have no water, no electricity, very limited communications."

"The main hospital is functioning without electricity. It is very difficult. There are no generators, they have been set aside because of the flooding," the prime minister said.

Authorities in Guadeloupe said that two people died there from the effects of Maria, while unconfirmed media reports put the storm death toll in Puerto Rico at six.