More than 5,000 people flocked to Ocean Park for the panda twins' debut, its chairman revealed on Monday, saying the figures fell within expectations.

Paulo Pong said that dozens of people arrived at the park gates at 6am, four hours before the start of public viewings.

He noted entry to facility was smooth as several drills had been conducted earlier.

The turnout marked a daily record high at the Giant Panda Adventure exhibition zone, Pong said, with a majority of them being locals.

"This included annual pass holders, who are devoted fans of pandas. There were also visitors from around the world and the mainland, including Chengdu. Many people from foreign countries, like Southeast Asia, or even Europe and America, came to see the pandas," he said.

"Some of the tourists actually didn't know about the twins when they arrived at Ocean Park, but when they heard they could visit the cubs, they also queued to meet them."

Public viewing of the twins, whom Ying Ying gave birth to last August, is for five hours daily – from 10am to 3pm.

But Pong said visiting hours could be extended.

"When they're more adapted to meeting the public, or even when they can be in the same exhibition zone with Ying Ying, then we can gradually extend the duration."

He said Ocean Park received hundreds of applications for the HK$1,500 VIP session to meet the cubs for 30 minutes before the park opens each day.

The first session will be held on Tuesday.

Pong emphasised that income generated from the special tour would be used for its conservation fund after deducting expenses.