A suspected World War II bomb was found at a Queen Mary Hospital construction site at around 4pm on Tuesday.
Around 50 workers were evacuated and the surrounding area in Pokfulam was sealed off. Only emergency vehicles were allowed within a 100 metre radius of the site.
Ms Chan, a site clerk at the scene, told Apple Daily that workers had been digging and found the suspected explosive, which was the size of a human arm.
A spokesperson for Queen Mary Hospital said that services at the hospital and ambulances were not affected. However, office buildings in the vicinity and a hostel for nurses were required to evacuate.
Police are investigating.
The redevelopment plan for Queen Mary Hospital was approved by the government in 2012. The works started in 2014.