Deputy Prime Minister Tony Tan was quoted by NewsRadio 93.8 as saying that while military aircraft were equipped to defend themselves from incoming missiles, commercial airlines were not.

Tan, who is also coordinating minister for security and defence, said it may take a year or two before planes with flag carrier Singapore Airlines and its regional subsidiary, SilkAir, can be equipped with anti-missile defence systems.

The vulnerability of commercial aircraft was highlighted in November last year when a DHL cargo jet was hit by what was believed to be a shoulder-fired missile near Baghdad International Airport in Iraq.

In November 2002, a missile was fired at an Israeli charter aircraft in Mombasa, Kenya, but missed.

The US Department of Homeland Security last month said it has commissioned research into ways to adapt anti-missile defence systems used on military planes to civilian aircraft.

Terrorism experts have expressed concern over the easy availability of shoulder-fired missiles in the weapons black market which could be used by militant groups.

In a speech at a programme launching this year's "total defence" campaign, Tan warned the threat of terrorism is likely to remain.

"We have to learn to live with this threat by taking appropriate measures and making necessary adjustments to our daily lives," said Tan, a former defence minister.

"We need to be more vigilant and keep an eye out for suspicious activity."

Singapore, a small island-republic, launches the campaign annually to encourage the public to help the military, police and civil defence forces to defend the country from any threat.

The campaign also stresses economic strength, social cohesion and the psychological resilience to weather crises.

Among the highlights of the programme is an exhibit by the elite Chemical, Biological, Radiological and Explosive Defence group on the armed forces' capabilities to deal with terrorist attacks involving biological or chemical weapons.

WAR.WIRE