White tigers are popular in zoos because of their unusual colouration
A cleaner at Singapore Zoo has died after being mauled by three tigers.
Nordin Bin Montong was attacked by the white Bengal tigers after crossing a moat surrounding their enclosure. He was reportedly acting erratically.
Zookeepers raised the alarm after they heard the screams of horrified visitors.
They managed to distract the tigers and pull Mr Nordin away but he died of his injuries on the way to hospital. Police are investigating the incident.
The Straits Times newspaper in Singapore says witnesses saw the cleaner climb into the enclosure and wade through the 10m (33-foot) wide moat.
He then approached the tigers with a broomstick and a bucket.
According to the paper, the largest tiger lunged at Mr Nordin who fell immediately and recoiled into a foetal position.
Officials at the zoo say the cleaner had been seen earlier behaving erratically.
"Police are still investigating. We are not able to say exactly what happened," said the assistant director of zoology, Biswajit Guha.
"But he was throwing things around and passing comments like 'goodbye, you won't see me again'," said Mr Guha.
An Australian couple visiting the zoo told the Straits Times they had seen Mr Nordin shouting and throwing things as he walked past a crocodile earlier in the day.
Singapore Zoo has closed the white tiger exhibit as a precautionary measure.