When a truck carrying 100 monkeys to a laboratory crashed in Pennsylvania, four of them escaped, prompting a police search and a warning to the public not to approach the animals.

On Friday afternoon, the vehicle collided with a dump truck near Danville, Pennsylvania, on its way to a laboratory in Florida.

Oh great. Lab monkeys are on the loose in Pennsylvania now pic.twitter.com/l6ncanAwtp

— Jack Posobiec 🇺🇸 (@JackPosobiec) January 22, 2022

According to police, four monkeys "fled the crash scene into the surrounding area."

It has been reported that three monkeys were later captured, but one was still on the run on Saturday morning.

The cynomolgus monkeys were tracked down using a police helicopter equipped with thermal cameras, while officers on the ground used powerful flashlights, local WNEP news site reported.

On its account, Pennsylvania State Police posted an image of a primate perched in a tree off Route 54 throughout the freezing cold night.

According to a reporter, police surrounded the monkey before firing shots from an unidentified weapon.

"Crash Update: There is still one monkey unaccounted for, but we are asking that no one attempt to look for or capture the animal," troopers tweeted.

Crash Update: There is still one monkey unaccounted for, but we are asking that no one attempt to look for or capture the animal. Anyone who sees or locates the monkey is asked not to approach, attempt to catch, or come in contact with the monkey. Please call 911 immediately.

— Troopers Andrea Pelachick & Lauren Lesher (@PSPTroopFPIO) January 22, 2022

It is worth mentioning that cynomolgus monkeys, also known as long-tailed macaques, can cost up to $10,000 each and are in high demand for coronavirus vaccine research, according to The New York Times. They can live in captivity for up to 30 years.