The United States consulate is warning Americans worldwide to be on alert following the release of a recent audio tape attributed to Osama bin Laden, the man believed to be behind the September 11 attacks.

The embassy forwarded to this newspaper a US State Department announcement which urged Americans to remain vigilant.

"The US Government continues to receive credible indications that extremist groups and individuals are planning additional terrorist actions against US interests. Such actions may include, but are not limited to, suicide operations. Because security and security awareness have been elevated in the US the terrorists may target US interests overseas. We remind American citizens to remain vigilant with regard to their personal safety and to exercise caution."

The announcement, which was dated October 10, goes on to say that terrorists do not distinguish between official and civilian targets.

"Attacks on places of worship and schools, and the murders of private American citizens demonstrate that as security is increased at official US facilities, terrorists and their sympathisers will seek softer targets. These may include facilities where Americans are generally known to congregate or visit, such as clubs, restaurants, places of worship, schools or outdoor recreation events.

Americans should increase their security awareness when they are at such locations, avoid them or switch to other locations where Americans in large numbers generally do not congregate. American citizens may be targeted for kidnap or assassination."

Meanwhile Government House will today be announcing details of an "anti-terrorism" exercise to be conducted this week.