Thirteen research monkeys were on the loose Monday after an additional five of the 43 primates that escaped from a research lab in South Carolina last week were captured unharmed, authorities said.

The discoveries on Monday — first there were three, then two more — mean 13 of the Rhesus macaques remain outside the Alpha Genesis Primate Research Center in the town of Yemassee, South Carolina.

In a statement, the Yemassee Police Department cited Alpha Genesis CEO Greg Westergaard for news of the day’s discoveries. “Additional primates have been successfully recovered today, all appearing to be in good health,” the department said.

Over the weekend, Yemassee police said 25 of the escaped monkeys had been captured safely.

A group of the monkey had amassed along the facility’s fence line, where many had bedded down for sleep overnight, the department said Sunday.

Police in the town, about 60 miles west of Charleston, have urged neighbors to be vigilant and keep doors and windows closed and secured.

“Efforts to safely capture the remaining primates will continue throughout the evening and as long as necessary,” police said Monday.

The department added, “We cannot stress enough the importance of the public avoiding the area, and under no circumstances should drones be operated near the facility, as they can startle the animals and cause further stress.”

Westergaard said a caretaker failed to lock two of a new enclosure’s doors during feeding and cleaning, leading to the Nov. 6 escape.

Alpha Genesis provides “nonhuman primate products and bio-research services,” according to its website. Westergaard has said it used a macaque to aid research into brain disease disorder treatments.

Last week’s escapees were described as very young Rhesus macaque females weighing just 6 to 7 pounds and, as yet, unexposed to research.