One of 43 monkeys bred for medical research that escaped a compound in South Carolina has been recovered unharmed, officials said Saturday.

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

The Rhesus macaques made a break for it Wednesday after an employee at the Alpha Genesis facility in Yemassee didn’t fully lock a door as she fed and checked on them, officials said.

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

Alpha Genesis CEO Greg Westergaard relayed that efforts to recover all the animals will persist throughout the weekend and for as long as it takes, the statement said.

Westergaard told CBS News on Thursday that a caretaker inadvertently failed to secure a door at the enclosure, allowing the monkeys to roam free.

“It’s really like follow-the-leader. You see one go and the others go,” he said. “It was a group of 50 and 7 stayed behind and 43 bolted out the door.”

Westergaard acknowledged that it would be a long process to get them back and that they didn’t want to chase the monkeys because that would spook them and make them run away.

“We’ve got them very close,” he told CBS News. “This is all like what we want to see.”

The monkeys are about the size of a cat. They are all females weighing about 7 pounds.

Alpha Genesis, federal health officials and police all said the monkeys pose no risk to public health. The facility breeds the monkeys to sell to medical and other researchers.

Alpha Genesis provides primates for research worldwide at its compound in Yemassee, about 50 miles (80 kilometers) northeast of Savannah, Georgia, according to its website.