Florida Gov. Rick Scott on Monday announced 10 new cases of locally transmitted Zika, bringing the total number of local cases to 14, as federal health officials issued a travel warning for the area where the virus has been found.

The outbreak is so far limited to a 1-square mile area just north of downtown Miami and has affected two women and 12 men, Scott said Monday. The Centers for Disease Control and Prevention on Monday urged pregnant women to avoid travel to that part of Miami.

Scott announced just last week that the state believed it had seen the first cases of Zika contracted via mosquitoes in Florida. Before that, all the cases in the U.S. were thought to be the result of infection outside the U.S.

Scott has called upon the Centers for Disease Control and Prevention to activate a CDC Emergency Response Team to assist the Florida Department of Health (DOH) to investigate, collect samples and assist in mosquito control efforts. Zika can be diagnosed in people without symptoms through blood and urine tests.

"Following today's announcement, I have requested that the CDC activate their emergency response team to assist DOH in their investigation, research and sample collection efforts," he said. "Their team will consist of public health experts whose role is to augment our response efforts to confirmed local transmissions of the Zika virus."

Zika typically causes a mild illness, and only one in five people get symptoms. However, it also causes a birth defect called microcephaly and is linked to a neurological disorder called Guillain-Barre Syndrome that can cause temporary paralysis.

"While we continue to learn more about this virus each day, we know that it is most harmful to pregnant women and their babies," Scott said. "For women who live or work in the impacted area and are either pregnant or thinking of becoming pregnant, I urge you to contact your OB/GYN for guidance and to receive a Zika prevention kit."

Six of the 10 people infected and were identified through door-to-door community outreach, state officials said. The Florida Department of Health has tested more than 2,300 people statewide for the virus.

The Food and Drug Administration last week asked all blood donation centers in Miami-Dade and Broward counties in Florida to halt blood donations until the blood can be tested for the Zika virus.

More than 1,600 cases of Zika have been found in the U.S. as of July 27, but almost all got the virus from a country or territory where it is spreading through mosquitoes. Bites from mosquitoes are the primary mode of transmission of the virus, but until last week government officials had not confirmed any mosquito-borne transmission of Zika.