Puerto Rican officials have urged the north-eastern Caribbean island's 3.8 million residents to prepare.

Shoppers have been emptying shelves

Schools and businesses have been closed, non-essential government workers sent home and 332 shelters are preparing to open.

The sale of alcohol has been banned and prices of emergency supplies and basic foodstuffs have been frozen.

Dubbed "left-handed Lenny" for its unusual west-to-east motion, the hurricane was about 235 miles (380km) south-west of San Juan, Puerto Rico, at 2100 GMT, and heading east, according to the US National Hurricane Centre in Miami.

The storm has been classified a magnitude three hurricane, based on the five-point Saffir-Simpson scale - with five being the most severe.

Forecasters posted storm watches and warnings for the eastern rim of the Caribbean south to Montserrat, but they expect the storm to turn north-east on a track bringing it to Puerto Rico on Wednesday morning.

National Hurricane Centre meteorologist Robert Molleda said: "The rains and the winds will start affecting Puerto Rico by late this afternoon and tonight."

Lenny, the eighth hurricane of the Atlantic storm season, is heading east at around 17mph (28kph).

Flooding and landslides

The south coast of Puerto Rico is already saturated, and there are fears that the hurricane could cause flooding and landslides.

A storm surge up to 7ft above normal and large and dangerous battering waves are forecast to hit the island.

The National Hurricane Centre said Lenny was carrying up to 15in (38cm) of rain - and possibly more in mountain areas. The hurricane is also expected fo spawn isolated tornadoes.

Hurricane warning

A hurricane warning is in effect for Puerto Rico and the US and British Virgin Islands.

A tropical storm warning and hurricane watch has been issued for Dutch St Maarten, St. Eustatius, Saba, Anguilla, St Kitts and Nevis, Antigua and Barbuda, and Montserrat.

A hurricane watch has been issued for parts of the Dominican Republic

A tropical storm warning and hurricane watch are in effect for part of the Dominican Republic's south coast. A hurricane watch was lifted for Haiti, which shares the island Hispaniola with the Dominican Republic.

More than 500 people perished on Hispaniola in September 1998 when Hurricane Georges passed through, mostly because of mudslides and flooding.

Heavy rains have doused both countries since last week. On Tuesday, residents in the south of the island scrambled for high ground as Lenny's northern edge was expected to bring more water to mountainous areas particularly vulnerable to mudslides.

Authorities in Haiti said floods had destroyed 60% of rice, corn and banana plantations around the southern town of Les Cayes. They said several houses were washed away in Cavaillon, a village northeast of Les Cayes.