Heavy smokes can be seen billow out of the crater 200 meters away from the scene at about 7:46 p.m. following a loud noise in the Tonkin Street, leaving exclamation among the crowds watching the detonation.

Another controlled burning of the remaining explosive were carried out by the ammunition experts 28 minutes after the detonation, which caused no casualty.

A police spokesman said a total of 16 unstable and dangerous explosive articles were detonated during the move and other stable will be transported to appropriate place for disposal.

Several police explosive disposal vehicles were also sent to the scene to transport other stable explosive articles to police arsenal for further disposal.

The police spokesman said the police experts believed the explosive articles were left by British troops during the Second World War.

The rusted explosive articles, including grenades, cannon shells and bullets, were first found by drainage workers about three meters underground at the work site at Tonkin Street at about 9:00 a.m. Saturday.

Police and ammunition experts were called to the scene shortly after report and began digging for more explosive articles several meters underground.

Ammunition experts said some of the 570 explosive articles had to be ignited due to their dangerous and unstable conditions as they put sandbags around those unstable explosive article after finishing the searching.

A 200-meter circle around the work site was cleared off for the detonation while residents of two nearby buildings were also evacuated before police's detonation moves.

One section of Tonkin Street near the work site and one exit of the subway station exit were cordoned off for more than 10 hours to clear the way for the disposal.

After the detonation, police began to remove the blockage at about 9:20 p.m. around the scene about 13 hours after the seal-off and let those living in two nearby buildings return home.

During the daytime, police had to spray water onto the rusted explosive from time to time and put up tents over them to prevent explosives from going off under the direct exposure of sun light.