Miami, Sep 9 (IANS): Hurricane Irma, which is expected to cause havoc in southeastern US, has resulted in an evacuation order for over 5 million people throughout Florida, state authorities said.

Florida hurricane programme manager, Andrew Sussman said late Friday night that about 5.6 million Floridians have received the evacuation order due to the mortal threat that Irma poses, now a Category 4 hurricane and whose effects are expected to be felt statewide, reports Efe new.

"Not tonight. Not in an hour. Now," said state governor Rick Scott from the capital, Tallahassee, stressing on the urgency of people who have received an evacuation order to leave their homes and go to shelters.

On Thursday night, Scott ordered the shutdown of all state colleges and universities until next week in order to make them available as shelters from Irma's first effects, whose eye will reach South Florida on Sunday morning.

However, many shelters set up in Miami-Dade County and neighbouring Broward have closed their doors having reached their maximum capacity on Friday.

In Miami-Dade County itself an evacuation order has been issued for more than 650,000 people, the largest so far, as reported by local daily Miami Herald.

Between Thursday and Friday, the northern state highways have reported considerable traffic jams in what is already an unprecedented exodus of residents and tourists visiting South Florida.

Florida Power and Light Company (FPL), a leading provider of electricity in the state, has anticipated that at least 4.1 million clients will lose power as a result of the impact of Irma approaching Florida.

FPL forecast widespread damage in areas where it provides service in addition to significant impact on areas with more population and have already stationed 13,500 workers in the state, especially in South Florida, for rapid response to emergencies, the company said in a statement Friday.

In accordance with federal mandates, the firm has issued an Unusual Event statement to the US Nuclear Regulatory Commission to proceed with the gradual closure of the nuclear plants.

According to the National Hurricane Centre (NHC), projections indicate that Irma would pass more towards the western coast of the state, away from Miami which has the highest population density.

Currently, the hurricane made landfall in Cuba's Camaguey archipelago at 11 p.m. on Friday night.

At least 24 people were killed this week when Irma pummelled northern Caribbean islands such as Barbuda and the Virgin Islands.

When it had first made landfall on Wednesday morning, Irma sustained maximum wind speeds of at least 185 mph for at least 37 hours, longer than any storm on record.

The Red Cross estimates 1.2 million people have already been battered by the storm.