MIAMI --Aerial insecticide spraying to combat mosquitoes carrying the Zika virus is underway in Miami Beach.
A plane carrying the insecticide naled released the spray over the Atlantic Ocean before dawn Friday.
The Miami Herald quotes Miami-Dade County officials as saying that on-board meteorological equipment was used to measure weather conditions and calculate a flight pattern that would allow the wind to carry the spray over the island.
The next round is scheduled for 6 a.m. Sunday.
Some residents oppose spraying, citing the potential for harmful effects. But county officials say the low concentration of naled won't harm them.
"We are concerned that the naled actually has more of a potential risk of creating the problems we are trying to avert than the actual concern with Zika," said area resident Brik Viera.
Local television stations reported that some parents kept their children home from school on Friday because of the spraying.
Aerial spraying targets adult mosquitoes; different pesticides for larvae will be sprayed on the ground.
South Beach is the second site of Zika transmission by mosquitoes on the U.S. mainland. The discovery in August led the U.S. Centers for Disease Control and Prevention to include a section of Miami Beach in a travel warning issued for pregnant women. Earlier in the summer, a travel warning was issued for Miami's Wynwood arts district, which is popular for day trips.
Zika infection can cause severe brain-related birth defects, including a dangerously small head, if women are infected during pregnancy.
Of Florida's 56 non-travel-related Zika cases, 11 are associated with Miami Beach.