Dieu Nalio Chery / AP

A doll covered by mud lies on the floor of a flooded house after the passing of Tropical Storm Isaac in Port-au-Prince, Haiti, Aug. 26. The death toll in Haiti from Tropical Storm Isaac has climbed to seven after an initial report of four deaths, the Haitian government said Sunday.

Tropical Storm Isaac lashed south Florida with strong winds and heavy rain on Sunday after battering the Caribbean, and officials said it could strengthen into a hurricane by midweek as it heads toward the Gulf Coast.

Emergency management and law enforcement officials in Key West ordered visitors and residents to remain indoors when the system moves through the island chain. “You’ve chosen to remain in the Keys during this storm and the only safe place for you to be is indoors,” said Monroe County Emergency Management Director Irene Toner. “Stay off roads and don’t go outside.”

Reported by NBC News staff and wire reports

Read the full story and see the slideshow below.

Slideshow: Isaac bears down on Florida Keys

Alan Diaz / AP

Tropical Storm Isaac rakes the Dominican Republic, Haiti and Cuba as it begins to head into the Gulf of Mexico.

Launch slideshow

 Follow @msnbc_pictures