Bomb disposal officers detonated a grenade near a popular hiking trail on Hong Kong Island following a discovery by a member of the public on Saturday.

A man reported at 10.36am that he had found what he believed to be a Japanese grenade on a slope near the Wong Nai Chung Tree Walk in Happy Valley, police said.

Three officers from the explosive ordnance disposal bureau detonated the grenade at around 1.15pm at the site, which is near 145 Wong Nai Chung Gap Road.

A police spokeswoman later said it was a Japanese-made Type 91 grenade that measured 7cm by 12cm.

The detonation made a loud noise which reverberated like a gunshot on the quiet slopes.

Happy Valley resident Nick Forsey, 46, who works in product sourcing, was in the area with his dog on their regular weekend walk when police conducted the explosion.

“I thought it was a gunshot,” he said, after learning from a Post reporter that it was a grenade. “It scared the life out of my dog.”

The site is near the Hong Kong Cricket Club and close to a section of the 50km Wilson Trail.

It is the latest in a string of discoveries of buried wartime explosives across Hong Kong Island.

In 2021, four grenades and a mortar from World War II were unearthed from a slope close to the Wilson Trail in the Tai Tam Country Park near Stanley. The explosives were detonated at the scene.

The bureau detonated five grenades thought to date from the second world war after a military enthusiast found the explosives in the same area in 2020.

The southern tip of Hong Kong Island has had military significance, especially during the Battle of Hong Kong in 1941. The Hong Kong garrison, composed of British, Indian and Canadian units, set up strongholds in some parts of southern Hong Kong such as the Stanley peninsula during the defence against the 1941 invasion by Japanese forces.

Wong Nai Chung Gap, where the grenade was discovered on Saturday and which connects the north and south of Hong Kong Island, had also been a key battleground during the battle.