A hunt is on for 43 monkeys that have escaped from a medical research compound in South Carolina.

Yemassee Police Chief Gregory Alexander said there was “almost no danger” to the public.

“They are not infected with any disease whatsoever. They are harmless and a little skittish,” he said.

The Rhesus macaque primates escaped from the Alpha Genesis facility on Wednesday (local time), after a new employee failed to properly close an enclosure, Alexander said.

The monkeys are females weighing about three kilograms and are so young and small that they have not been used for testing, police said.

Alpha Genesis employees “currently have eyes on the primates and are working to entice them with food”, police said on Thursday.

The company usually handles escapes on site but the monkeys got outside the compound, which is about 1.6 kilometres from downtown Yemassee, Alexander said.

“The handlers know them well and usually can get them back with fruit or a little treat,” he told the Associated Press by phone.

But rounding up the escapees is taking some more work.

Alpha Genesis was  setting up traps and using thermal imaging cameras to recapture the monkeys on the run, Alexander said.

Nearby residents have been urged to shut their windows and doors so the monkeys can’t find a place to hide inside homes. Anyone who sees any of the runaway primates has been asked to call police so the animals can be recaptured.

Alpha Genesis provides primates for research worldwide at its compound, which is about 80 kilometres north-east of Savannah, Georgia, according to its website.

The company did not respond to an email asking about Wednesday’s escape.

In 2018, federal officials fined Alpha Genesis $US12,600 ($18,900) after dozens of primates escaped. There was also another incident that left some animals without water, and problems with how the monkeys were housed.

Officials said 26 primates escaped from the Yemassee facility in 2014 and another 19 got out in 2016.

-AAP