Hurricane Melissa live updates: No official death toll in Jamaica

No fatalities have been reported so far in Jamaica since Melissa made landfall, Desmond McKenzie, deputy chairman of Jamaica's Disaster Risk Management Council, said during a press briefing based on preliminary information.

McKenzie noted it's still early, as response crews haven't been able to reach the worst-hit areas yet.

Jamaican officials had reported Monday that three people died in Jamaica amid preparations for the storm.

During his briefing Tuesday, McKenzie said at least three families were trapped in Black River, and that rescue teams were trying to reach the area.

He described the impacts of Hurricane Melissa on several regions of the island.

The southwestern parish of St. Elizabeth is flooded and parts of Clarendon are also reporting extensive damage, he said. There have also been reports of flooding, fallen trees, power outages, landslides and storm surges, especially in St. Thomas, Portland and St. Catherine, he said.

Four main hospitals on the island all sustained damage, he said.

Nearly 6,000 people are in shelters across Jamaica as of Tuesday afternoon, according to McKenzie.

The State Department said it has received a formal request for assistance from the government of Jamaica and is working with the government to assist people affected by Hurricane Melissa.

The department has prepositioned emergency relief supplies in six warehouses that will allow for the distribution of emergency relief supplies to people affected by the storm, a State Department official tells ABC News.

The official said that the State Department "maintains warehouses around the world from which we can distribute lifesaving aid in the aftermath of natural disasters."

-ABC News' Mariam Khan

The Norman Manley International Airport in Kingston, Jamaica, could reopen to start accepting emergency relief flights as early as Thursday, officials said Tuesday.

The impact on the airport is "not extensive," Jamaica's energy, telecommunications and transport minister, Daryl Vaz, said during a briefing.

The center of Melissa is now moving off the northwest coast of Jamaica as a Category 4 hurricane with maximum sustained winds currently at 145 mph.

The center is currently located about 15 miles east of Montego Bay.

Strong, damaging winds, catastrophic flash flooding and life-threatening storm surge continue to hit parts of the island nation.

The core of Melissa is expected to move away from western Jamaica on Tuesday evening, moving back over the warm waters of the Caribbean Sea as it closes in on southeastern Cuba next.

Melissa is forecast to make a second landfall later Tuesday night along the coast of southeastern Cuba, west of Guantanamo Bay, potentially re-strengthening a bit as it moves across warm water again over the next several hours.

-ABC News' Dan Peck