Miami Beach now has cases of Zika infection that appear to have been locally transmitted, US media reported on Thursday, suggesting that the mosquito-borne virus is spreading in Florida.

The Miami Herald reported a new zone of Zika transmission has been identified in the resort city, citing unnamed local health sources.

The New York Times also reported "a cluster" of Zika cases most likely transmitted by local mosquitoes in Miami Beach, citing an unnamed health official.

The report described "a handful of cases" in which Zika likely spread among people in close proximity to each other. It added that an official announcement could come later Thursday or Friday.

Last month, Florida announced its first cases of local Zika transmission in Miami, in a one-square mile section of the arts neighborhood of Wynwood, north of downtown.

Florida now has 35 cases of local Zika transmission. A total of 25 of those cases have been traced to Wynwood.

Contacted by AFP, a spokeswoman for the Department of Health declined to comment on the Miami Beach reports.

She said investigations are ongoing in "areas in Miami-Dade and Palm Beach Counties where local transmissions of Zika may have occurred."

However, the state health department "still believes active transmissions are still only occurring in the area that is less than one square mile in Miami-Dade County."

Florida is so far the only state in the mainland United States where local spread of Zika has been reported.

Florida Governor Rick Scott released a statement Thursday afternoon that called on state business and health associations to work with the tourism industry on Zika prevention and education.

He also called on the state department of health to offer hotels, restaurants and attractions in Miami-Dade County mosquito spraying at no cost.