Hurricane Maria has strengthened to a “potentially catastrophic” category five storm, US forecasters say, as it bears down on islands in the Caribbean.
The island of Dominica is one of the first in its path, facing sustained winds of 260km/h (160mph).
Maria is moving roughly along the same track as Irma, the hurricane that devastated the region this month.
Martinique declared a maximum-level alert while another French island, Guadeloupe, ordered evacuations.
Hurricane warnings are also in place for:
Dominica: A former British colony with a population of 72,000 about half way between Guadeloupe and Martinique. The eye of the hurricane was about 15 miles (25km) east-south-east at midnight GMT
Puerto Rico: The US territory expects Maria to make landfall as a category three on Tuesday. It escaped the worst of Irma and has been an important hub for getting relief to islands more badly affected. Governor Ricardo Rossello urged islanders to seek refuge
US Virgin Islands and British Virgin Islands: Both island chains suffered severe damage from Irma and President Donald Trump declared a state of emergency for the US territories on Monday. British authorities fear debris left behind by Irma could be whipped up by the new storm and pose an extra threat.
Warnings are also in effect for St Kitts and Nevis, Montserrat and St Lucia while hurricane watches are in place for St Martin, Saba, St Eustatius and Anguilla.
Some of these islands are still recovering after being hit by Hurricane Irma – another category five hurricane which left at least 37 people dead and caused billions of dollars’ worth of damage
The islands bearing the brunt of Maria are part of the Leeward Islands chain and include Antigua and Barbuda. The latter was evacuated after being devastated by Irma.
The US National Hurricane Center (NHC) increased the strength of Maria in just a few hours on Monday from a category two storm, to a category four and then to category five – the highest level.
Forecasters warned that heavy rainfall caused by the hurricane “could cause life-threatening flash floods and mudslides”.
The British government said more than 1,300 troops were staying put in the region and an additional military team had been deployed to the British Virgin Islands.
In the French territory of Guadeloupe, schools, businesses and government buildings have all been closed and severe flooding is predicted. The French government has ordered low-lying areas on the islands to be evacuated, AFP reports.
Earlier this month, Irma left more than two-thirds of homes on the Dutch side of the island of St Martin (known as Sint Maarten) uninhabitable, with no electricity, gas or drinking water.
The French government has said its side of St Martin – known as Saint-Martin – sustained about €1.2bn ($1.44bn; £1.1bn) in damage, with nine deaths across Saint-Martin and nearby St Barts.