Maximum sustained winds have increased to near 135 mph with higher gusts. This makes Michelle a category four hurricane on the Saffir-Simpson hurricane scale

US National Weather Service warning

It was upgraded to a category four hurricane overnight with speeds of 135 mph (220 km/h) and higher gusts.

The 20 deaths in Nicaragua and Honduras came after Hurricane Michelle brought torrential rain and flooding.

Ten people are confirmed dead in Honduras, where some coastal areas received half their usual annual rainfall in the last five days.

Some 50 people are still missing on Nicaragua's Atlantic coast after floodwaters three metres deep tore through coastal towns.

Hurricane Michelle is in the open sea south of Cuba, where it is expected to arrive early on Sunday.

Forecasters say within the next 12 hours winds of up to 150 mph will batter the capital Havana before it continues to move slowly northwards towards the United States.

Florida on alert

Florida has put its emergency operation plan into force, even though the hurricane is still several hundred miles away.

Homes and businesses are already being boarded up in southern Florida, and people are being advised to stock up on food.

Long queues are starting to develop on the roads, as all non-residents of the Florida Keys are advised to leave the area.

Emergency crews in Central America and Jamaica were digging out after five days of rain and floods that have left dozens missing and forced more than 115,000 to flee their homes.

The Honduran authorities said the damage wrought by the last few days of rains brings back memories of Hurricane Mitch, which killed 5,000 people and caused billions of dollars worth of damage in 1998.

Hurricane Michelle is moving slowly northwards

Rescuers finally reached tens of thousands of people left homeless by floods in Honduras.

Atlantic coast residents were reportedly trapped for days on rooftops or patches of high ground, and some were said to be surviving on the carcases of drowned farm animals.

In Nicaragua, officials say some 100,000 people have been made homeless by the hurricane.

In Jamaica, where two men are reported to have died in floods and mudslides, helicopters bringing food and aid on Saturday reached several villages cut off by flooding on the island's north-east coast.