Chester Zoo' s Monsoon Forest building has reopened, a day after four orangutans escaped there.

Female Subis and her infant offspring Tuti and Siska, as well as another orangutan called Indah, escaped into the sub-tropical Monsoon Forest exhibit, part of the Islands attraction.

Keepers acted quickly to safely usher them back into their enclosure just after 10am yesterday morning (Tuesday, June 28).

No visitors were in the vicinity at the time since the building was closed for a private event due to start later in the day, a zoo spokesperson said.

The Duke of Westminster had been visiting the zoo but was 'not involved in the incident', they added.

To be on the safe side, the zoo cordoned off the the area while they made sure the orangutan family and Indah were back safely with the rest of the group, and the Monsoon Forest remained closed for much of the day.

Today, however, a spokesperson said everything was back to normal.

"These situations are extremely rare but we have thorough safety procedures in place which enabled us to quickly guide the animals back into their habitat," he said.

"Our primate experts, alongside external contractors, have thoroughly checked the exhibit and the Monsoon Forest is open again today."