Soon after, Governor Ricardo Rossello issued an order for about 70,000 people living in the area to get out.

Puerto Rico was already battling dangerous floods after Hurricane Maria ravaged the island early on Wednesday. Rescuers raced against time to reach trapped residents.

Rossello called Maria the most devastating storm in a century after it destroyed the US territory’s electricity and telecommunications infrastructure.

Rossello told CNN the island is lacking communications and the preliminary assessment at this point is 13 fatalities.

“Right now our efforts are to make sure we have everybody safe, that we can rescue people. Our efforts have already produced almost 700 rescues so we’re clearly focused on that.”

The National Hurricane Centre said some areas in Puerto Rico could see more than a metre of rain from Maria, and Rossello warned of dangerous mudslides brought on by the deluge.

“We have a lot of flooding, we have reports of complete devastation of vulnerable housing. Of course it’s still raining over here.”

Hurricane Maria hammers Turks and Caicos in Caribbean after flooding Puerto Rico

Maria has been blamed for at least 33 deaths, including 15 in Dominica, three in Haiti and two in Guadeloupe.

After lamenting that Puerto Rico had been “absolutely obliterated” by Maria, US President Donald Trump spoke with Governor Rossello on Thursday night and promised to speed up relief efforts.

Although the southeast coast suffered the worst damage, no part of the island escaped the storm’s wrath, including the capital San Juan where there was widespread flooding.

The city’s mayor, Carmen Yulin Cruz, said the biggest need was getting emergency medication and supplies to vulnerable people who are stranded in their homes.

“Yesterday we were canvassing and we found elderly people that don’t have blood pressure medicine, food,” she said.

“I got an SOS from [a home for the elderly] and it was a text like from a horror movie. It said if anybody can hear us, please, we are stuck here and we can’t get out and we have no power and we have very little water left. We got there just in time.”

Hurricane Maria swamps parts of Dominican Republic, as powerless Puerto Rico faces months without electricity

The torrential rain turned roads into muddy brown rivers, impassable to all but the largest of vehicles.

Toppled trees, street signs and power cables were strewn across streets that were also littered with debris.

Puerto Rico’s electricity network has been crippled by the storm and engineers say it could take months for power to be fully restored.

The local electricity board has promised that their priority will be to restore power to hospitals, water treatment plants and pumping stations.

Brock Long, who heads the US federal government’s emergency management agency FEMA, said ships carrying millions of meals and bottled water were trying to dock as the island’s ports are slowly reopened.

As of Friday evening, Maria was a category 3 hurricane with winds of (205km/h, churning in the sea some 115 miles east of the southeastern Bahamas.

Heavy rains and high winds began hitting the archipelago, a British territory, on Thursday afternoon.

The government opened new shelters after several buildings which had been used during Hurricane Irma earlier this month were damaged and authorities feared they might not hold up under another fierce storm.

In the Dominican Republic, the heavy rains triggered flooding as rivers overflowed their banks.

High winds downed trees and electrical pylons, and 140,000 people were left without power, the government said. Some 17,000 have been evacuated from their homes.

Maria previously tore through several Caribbean islands, claiming the highest toll on Dominica, which has a population of around 72,000 and has been largely cut off from the outside world.