You don't really have an idea of how animals will behave until it happens

Toru Hirose Zoo employee

On Friday, the Ueno Zoo in Tokyo held its semi-annual drill to prepare for such an eventuality.

But given the obvious dangers of letting a live bear loose in a zoo packed with schoolchildren, the Ueno keepers have come up with an unorthodox solution.

According to the Reuters news agency, they dressed a colleague in a bear suit, and practised catching him instead.

'Useful' drill

The exercise was based on the premise that the walls of the enclosure had collapsed during an earthquake.

Undeterred by the make-believe, keepers dressed in hard hats stretched nets across paths and poked at the "bear" with long poles as it roamed the zoo, stopping only to savage a few passers-by.

The "bear" was finally "tranquillised", wrapped in a net and carted off.

Zoo employee Naoki Tabata said real breakouts have occurred, although not recently, and the drills were useful.

But Toru Hirose, who played the bear, saw limits to the usefulness of the exercise.

"You don't really have an idea of how animals will behave until it happens," he told Reuters as he donned the suit.

Harumi Tokiwa, a kindergarten teacher visiting the zoo with her pupils, said an escaped polar bear would be scary.

"I guess if that happened, we'd probably just be eaten."

Six-year-old Miyo Fujioka was undaunted.

"I'd get my brother who's learning karate to go and beat it up," she was quoted as saying.