The trust has now launched an investigation into how the pair of “young bears”, weighing about 180kg (397lb) each, escaped as there were no signs of enclosure damage, it said.
Mr Habben said: “Both bears are extremely happy. The team were very, very calm, as were the bears at all points.
“The public were not in harm’s way, emergency procedures and everyone did the job they were intended to do.”
Mr Habben said a “code red” was called after the bears were spotted by senior staff after they “breached” the enclosure and made their way to a staff area at about 15:00 BST on Monday.
He said: “They were in an area where we keep enrichment – all the nice things.
“The bears had a feast, played around, pulled some rope out.”