Newborn triplets in Mexico tested positive for coronavirus on the day of their birth.
The trio were born on May 8 to a mother who also had Covid-19, although she was asymptomatic.
The triplets are not believed to be in danger, Monica Rangel, the health secretary of northern state San Luis Potosi said.
She said the case was being studied to determine whether the triplets were infected before or after birth.
However, it appears improbable that they could have been infected outside the womb so quickly, Ms Rangel added.
This is not the first time newborns have tested positive for the virus, but it is rare.
The World on Coronavirus lockdown
It comes as the number of coronavirus cases in Mexico rapidly increases.
Nationwide, the country's confirmed coronavirus cases rose by 4,577 to 185,122.
The confirmed death toll also rose by 759 to 22,584.
However, both numbers are considered significant undercounts due to Mexico's very low levels of testing.
Officials said that levels of infections appear to have stabilised, and held out hopes - as they have many times before - that the numbers may start declining soon.
