Zoo staff are working to account for all species after fire destroyed much of the vast plastic roof covering Chester Zoo's Monsoon Forest area.

All the mammals have been located but keepers are "working hard" to track down the rest of the animals, according to a statement released by the zoo on Saturday.

However attempting to trace all the animals, which includes birds, will take "some time", they add.

The cause of the fire is being investigated.

Chester Zoo have confirmed that the zoo will be open to visitors on Sunday, but the Monsoon Forest building and Islands zone will be closed.

The zoo's lantern event will also go ahead on Sunday evening after Saturday's event was cancelled.

Video: Press Association

Eyewitnesses described how visitors to the attraction - billed as the largest indoor zoo exhibit in the UK - were rushed to safety as the blaze spread rapidly through the polymer roofing material.

Zoo staff led the animals housed in the structure to safety as firefighters rushed to the scene.

Orangutans, gibbons, crocodiles, turtles and exotic birds are among the species housed in the Monsoon Forest, which recreates a tropical south east Asian environment.

The fire was declared a major incident by Cheshire Fire and Rescue Service.

The zoo said in a statement: "Critically endangered Sumatran orangutans and other mammals are accounted for and being looked after by the zoo's specialist conservationists and vets.

"We are working hard to account for all other species, such as birds, and move animals to alternative habitats.

"Given that this is the UK's largest zoological tropical house, it will take some time.

The Leader:

"We will be working intensively in the coming days and weeks to do this."

The zoo released a full statement on Saturday evening.

It read: "Thank you for the overwhelming messages of goodwill following the fire in our Monsoon Forest building - they have been of great comfort to our teams.

"Many of you have expressed that you would like to come along to the zoo to show your support, so we are able to confirm that the zoo will be open to visitors tomorrow, Sunday 16 December. 

"The Monsoon Forest building and Islands zone will remain closed as our conservationists and vets continue to provide expert care and attention for the species there.

"The Lanterns event will go ahead tomorrow evening (Sunday 16 December) as planned.

"We can confirm that the fire service are still in attendance at our Monsoon Forest habitat after today’s fire.

"The fire has now been extinguished, but fire fighters will remain on site throughout the night alongside the zoo’s experts.

"Visitors were evacuated immediately and the zoo’s response team worked alongside the emergency services to help bring the situation under control.

"The cause of the fire is currently unknown, but we will be helping the relevant authorities with the investigation that will take place over the coming days and weeks.

"The zoo’s teams are now assessing the situation inside Monsoon Forest. Critically endangered Sumatran orangutans and other mammals are all accounted for and being looked after by the zoo specialist conservationists and vets.

"We are working hard to account for all other species, such as birds, and move animals to alternative habitats. Given that this is the UK’s largest zoo tropical house this will take some time.

"The zoo’s experts will be working intensively in the coming days and weeks to do this.

"The zoo’s The Lanterns event this evening has been cancelled and ticket holders notified by email.

"The zoo would like to thank the emergency services for their swift response.

"Thank you also to the many, many messages of public support."