Four people were killed in Haiti, where landslides destroyed several hundred houses, according to the UN Office for the Co-ordination of Humanitarian Affairs.
The Haiti deaths brought to at least nine the number of people killed by Dean since it hit the Caribbean as the first hurricane of what is expected to be an active 2007 Atlantic season.
The US National Hurricane Centre said Dean could gain even more strength on Monday to become a potentially catastrophic Category 5 as it passes south of the Cayman Islands and heads for Mexico's Yucatan peninsula.
|Tourists have abandoned resorts like Cancun|
in Mexico for fear of Dean's arrival [AFP]
Thousands of frightened tourists on Mexico's Caribbean coast stood in line for hours at airports to flee before Dean's expected arrival.
Mexico's Pemex oil company began evacuating 13,360 workers from its Gulf rigs.
The US space shuttle Endeavour hastily left the orbiting International Space Station so it can land a day early in case the storm forces Nasa to evacuate its Houston centre.
Dean is an "extremely dangerous" Category 4 hurricane, the second-highest on the five-step Saffir-Simpson scale.
It has packed winds of 230kph and its eye was about 215km west-southwest of Kingston at 11pm EDT (0300 on Monday GMT).
On Sunday, Garfield Buford, a journalist on the island, told Al Jazeera that Jamaicans were on full alert.
Category 1 – Winds 119-153kph
Minor coastal flooding and structural damage
Category 2 – Winds 154-177kph
Damage to roofs, mobile homes and shanty houses. Some trees uprooted. Small boats may break moorings
Category 3 – Winds 178-209kph
Damage to buildings, mobile homes destroyed. Severe flooding near to coast
Category 4 – Winds 210-249kph
Major structural damage, roofs destroyed. Storm surge around 5m requiring widespread evacuation of coastal areas
Category 5 – Winds 249kph or higher
Serious damage to all but strongest buildings. Severe flooding far inland, all trees blown down. Storm surge up to 6m above normal
He said: "The latest we are hearing is that the eye of the hurricane may not make land but it is expected to continue along the south coast of the island."
Portia Simpson Miller, Jamaica's prime minister, declared a month-long state of emergency and called a cabinet meeting to discuss the potential impact on August 27 general elections.
The power company switched off electricity as winds began to gather strength and waves battered the southern coast.
Police said they shot and wounded two men caught trying to break into a business in Kingston during the storm.
A man was missing after falling trees tore into his house.
The eye of the storm stayed just south of Jamaica but the winds around the calm centre buffeted the island.
Jamaica is a mountainous country of three million people.
Local media reported 17 fishermen and women had been stranded before the storm on the Pedro Cays, a small island chain south of Kingston.
The Jamaican government urged residents to go to shelters.
But many people, including those in one low-lying seaport town close to Kingston, refused to flee.
Eqecat Inc, a risk modelling company, estimated that insured losses from Dean's rampage through the Caribbean islands at $1.5bn to $3bn, most of it in Jamaica.