The billionaire wrote last week that he and his staff had hunckered down in his wine cellar on Necker Island, hoping to weather the 185mph storm safely.
"I'm donating $250,000 immediately - tonight - to the storm relief efforts in the U.S. Virgin Islands".
"Unfortunately some of the prisoners have escaped and are now armed".
Fifty-three police officers were also being deployed "to help sort things out, get these wonderful places back on their feet", Johnson said.
"I don't want to panic anyone but it's really important people are aware of the situation there". My house and my business have been blown away and destroyed.
Sources told Sky News that between 100 and 120 prisoners made the audacious escape from the prison.
Shadow global development secretary Kate Osamor said: "Boris Johnson was clear on Sunday that this is a national disaster being treated as though in Inverness, Dover or St Ives".
Asked why the United Kingdom had not airlifted its citizens out of the area before the hurricane struck, the Prime Minister's official spokesman said: "We are talking about a huge number of British citizens who are in the path of this hurricane, and we are doing everything we can to help them". He added that troops, police, medics and engineers were also being sent in.
Former San Antonio Spurs center Tim Duncan has largely stayed out of the spotlight after retiring from the National Basketball Association, but he penned an article for The Players' Tribune asking fans to help the Hurricane Irma recovery effort in the U.S. Virgin Islands.
"The UK government will have a massive role to play in the recovery of its territories affected by Irma", he said on his blog.
Officials feared the worst was yet to come with Jose heading toward the Caribbean, but the storm veered north without causing much damage.
Following criticism of its response to the disaster, the Government announced a £32 million aid package.
He said: "This is just the beginning". A awful thing has happened to British overseas territories.
Ms Elliott, 38, who was working overseas when the hurricane hit, had feared her family would run out of supplies before they were rescued, but has since told the Press Association that fiance Andrew, 10-month-old son Oscar, and 23-month-old daughter Isla are due to be evacuated to Puerto Rico on Tuesday.
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