COLUMBIA, S.C. (AP) — One of 43 monkeys bred for medical research who escaped from a complex in South Carolina has been found unharmed, officials said Saturday.

Many of the others are still within a few feet of the property, jumping back and forth over the facility’s fence, police said in a statement.

The rhesus monkeys made a break for it Wednesday after an employee at the Alpha Genesis facility in Yemassee failed to fully lock a door while feeding and checking on her, officials said.

The monkeys were exploring the outer fence of the Alpha Genesis complex on Friday and cooed at the monkeys inside. The primates continued to communicate with their companions at the facility on Saturday, which is a positive sign, the police statement said.

Alpha Genesis CEO Greg Westergaard said efforts to recover all the animals will continue through the weekend and for as long as necessary, the statement said.

The monkeys are about the size of a cat. They are all females and weigh about 3 kilos.

Alpha Genesis, federal health officials and police all said the monkeys do not pose a risk to public health. The facility breeds the monkeys to sell to medical and other researchers.

Alpha Genesis supplies primates for research around the world at its facility in Yemassee, about 50 miles northeast of Savannah, Georgia, according to its website.