Five crew members remain unaccounted for following a collision between the Indonesian-registered tanker Kartika Segara and a Dominican-registered dredger named JBB De Rong 19 in Singapore territorial waters on Wednesday at around 12.40am local time.

According to the Maritime and Port Authority of Singapore (MPA), the collision took place approximately 1.7 nautical miles south-west of Sisters Island.

The incident occurred when the dredger was passing the westbound lane and the tanker was departing Singapore to join the eastbound lane of the Traffic Separation Scheme in the Singapore Strait.

The dredger capsized after the collision and remains partially submerged.

A total of 12 personnel, including 11 Chinese and one Malaysian national, were on-board the dredger at the time of incident.

The Singapore Police Coast Guard has so far rescued seven of the Chinese crew members.

The tanker suffered has damage as a result of the incident, but all 26 Indonesian staff were reportedly unharmed during the collision.

MPA said in a statement: “MPA is leading the Search and rescue (SAR) operations and relevant Singapore agencies are rendering all assistance.

“Two MPA tugboats have moved the partially submerged dredger safely to an area near Pulau Senang for follow-up underwater search operations.

“In addition, MPA has deployed three patrol craft to assist in the SAR operation and the Republic of Singapore Navy, SCDF and PCG have also deployed a total of seven vessels on scene to support the SAR.”

MPA further noted that shipping traffic in the Singapore Strait is flowing as usual following the incident.

The agency is currently investigating the cause of the incident.