Guests staying at Sydney's Taronga Zoo on Tuesday night were woken to the sound of an alarm and staff reportedly telling them to run for safety.
Sydney couple Dominique and Magnus Perri were staying on-site with their children as part of the "Roar and Snore" program which offers an up close and personal safari experience.
But their stay was interrupted when five lions escaped their enclosure on Wednesday morning, several hours before the park was due to open to the public.
Mr Perri said zookeepers woke them up at around 6:40am.
"They came running into the tent area saying, ‘this is a Code One, get out of your tent and run, come now and leave your belongings’," he told The Sydney Morning Herald.
A code one means there's an incident involving a dangerous animal.
The guests ran into a nearby building some 70 meters away. Staff counted them and locked the door, he said.
At first, staff supposedly thought it was a drill, but they quickly learned it wasn't.
"They told us they have this sort of training every now and then, but then we heard on the radio ‘They are still outside’, so we realised something was out there, and they said, ‘It’s the lions’," he explained.
Zoo staff 'acted swiftly' as 'significant incident' unfolded
Taronga Zoo confirmed the "emergency situation" occurred out at 6:30 am but was "under control in minutes".
In a statement, the zoo revealed five lions – one adult and four cubs - were located outside their main exhibit.
The zoo "has strict safety protocols in place for such an incident", they confirmed in its initial statement.
"All zoo staff acted swiftly, and procedures and processes were followed as they should have been," it later said.
"We have since reviewed video footage, and we have confirmed it was less than 10 minutes between the lions exiting the main exhibit, and the emergency response being enacted."
NSW Police were called to the scene as a precaution, with helicopter footage showing officers inside the enclosure.
"All persons on site were moved to safe zones and there are no injuries to guests or staff. All animals are now in their exhibit where they are being closely monitored," the zoo said.
"The lions were observed in a small area adjacent to the main exhibit, where a six-foot fence separated them from the rest of the zoo."
The zoo confirmed four of the lions "calmly returned to their dens", and one cub was safely tranquilised. The cub is now awake and well.
"This is a significant incident, and a full review is now underway to confirm exactly how the lions were able to exit their main exhibit," they said.
Nearby residents in Sydney’s lower north shore reported hearing an automated alert telling them to stay in their houses, according to the Sydney Morning Herald.
Taronga Zoo is among Sydney's most iconic tourist attractions and houses more than 2,000 species.
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