The sign for Wynwood Yard is seen in the Wynwood arts district of Miami, Florida, U.S. August 3, 2016. REUTERS/Joe Skipper

CHICAGO (Reuters) - Three more people in Florida have tested positive for Zika caused by local mosquitoes, including another person who does not live in the one-square-mile (2.6-square-km) area believed to be the hub of local transmission, state officials said on Friday.

Florida now has 28 cases of non-travel-related Zika, a virus that spread rapidly across Latin America and the Caribbean.

The U.S. Centers for Disease Control and Prevention has issued a warning for pregnant women to avoid this area of Miami. Zika has been shown to cause birth defects, including microcephaly, which causes severe developmental problems.

As of Friday, two individuals in Miami-Dade County have been infected with Zika through local transmission who live outside the transmission area. A third person in Palm Beach County has also tested positive for Zika.

The health department said it still believes local transmission is only occurring in the one-square-mile (2.6-square-km) area located in the Wynwood neighborhood of Miami.

The state said is has just begun investigating the second Miami case outside of the Wynwood neighborhood and has begun mosquito control efforts.

It did not disclose the location of the new case and stressed that one case does not mean active transmission. In addition to cases caused by local transmission, Florida reported 10 new travel-related cases of Zika, bringing the total to 413.

The continuing Zika outbreak was first detected last year in Brazil, where it has been linked to more than 1,700 cases of the microcephaly, and has since spread rapidly through the Americas. Its arrival in the continental United States had been widely anticipated.

(Reporting by Julie Steenhuysen; Editing by Jonathan Oatis)