SINGAPORE - A vessel crew member, who had just disembarked at Marina South Pier, looked nervous and refused to make eye contact with others.

Alerted to his suspicious behaviour, immigration specialist Kasbiah Senan immediately stepped in for checks and subsequently found a switchblade, which was a prohibited item, hidden in his pocket.

On Friday, the 53-year-old and frontline officers from the Immigration and Checkpoint Authority (ICA), received thanks for her contributions to Singapore's border security by Senior Minister of State for Home Affairs and National Development Desmond Lee.

He was on a visit to the Singapore Cruise Centre to understand the roles of ICA in ensuring security and efficient clearance at a sea checkpoint.

"Our checkpoints are a very important frontline defence against terror. So, it is critical for ICA and the Home Team departments to focus their efforts on heightening security. It is a coordinated effort," he said. At a sea checkpoint, these departments would include the police coast guards, Maritime Port Authority and the navy.

About 12 million passengers and crew members are cleared at the sea checkpoints each year, with a total of 18 such checkpoints in Singapore, said Mr Lee.

Stressing that the community also plays an essential role, he said: "People who work here, people who work at our checkpoints and fellow passengers can help us keep an eye out for suspicious persons and items. This would help play a part in ensuring security."

Besides immigration officers, employees at all checkpoints, including cleaners, cashiers, retail and counter staff, are required to undergo training as part of the Threat-Oriented Passenger Screening Integrated System (Topsis).

As the eyes and ears on the ground, they are trained to keep a lookout for suspicious passengers in and around the premises.

On his visit, Mr Lee also observed how officers conducted checks on board a ferry at the jetty, as well as the use of a puffer portal, which is a full-body system to detect explosive and narcotic particles.

He also viewed how the BioScreen is used to capture the fingerprints of anyone who enters Singapore. In January, Mr Lee announced in Parliament that additional biometric screening will be rolled out at all checkpoints from June.