Australian security experts warned on Monday that terrorists could swap explosives for computers to wreak death and destruction around the world, with the Sydney 2000 Olympic Games a prime target.

"Techniques of `information warfare' may be employed by terrorist organizations with no less effect than the traditional bomb," security researchers Russell Smith and Peter Grabosky said in a study released at an Australian Institute of Criminology computer crime conference on Monday.They warned that authorities around the world had failed to grasp the potential for computer terrorism, which includes hijacking air-traffic-control systems to crash planes and cutting power supplies.

"Widespread death or injury has yet to occur as a result of hacking," they said.

Terrorists could also take hostage computerized services such as telecommunications and power supplies, Grabosky later told Reuters.

"Many of these things depend on software and the convergence of computing and communications, and they could be vulnerable to disruption by pranksters, extortionists or terrorists," he said.

Squadron leader Nigel Thompson, an Australian air force analyst, warned the conference that the Sydney Olympics presented a prime target for computer terrorists.

"For Australia, the Sydney 2000 Olympics could provide a period of heightened sensitivity to cyber-terrorism and any of the numerous issues of discontent in the domestic, regional or global communities could provide a motive," he said.

Thompson said computer terrorism could also be used in non-deadly attacks to disable the armed forces or throw their operations into chaos. Such attacks could be launched via the Internet, he said.

"Possibly the greatest danger to a nation is where it exposes itself widely to attack via the Internet - exposed in such a way that the nation's interests can be attacked directly via the Internet, where defenses may be totally inadequate," Thompson said.

Grabosky and Smith said authorities needed to change their attitudes to take on computer terrorism.

"Some people regard their information systems with a degree of nonchalance," Grabosky said. "It's the contemporary equivalent of leaving your home with the door unlocked.

"We're at the dawn of an age of electronic commerce, and ensuring it can flourish while minimizing the risks of illicit exploitation is a real challenge."