US warns of possible al Qaeda plane attacks

The US Department of Homeland Security has warned the airline industry of possible suicide hijackings and bombings by Osama bin Laden's al Qaeda network for the rest of the summer.

"At least one of these attacks could be executed by the end of the summer 2003," the department said in an advisory sent out on Saturday and described by US officials yesterday.

"Al Qaeda planners have primarily considered suicide hijackings and bombings as the most promising method to destroy aircraft in flight as well as to strike ground targets," the advisory said.

The officials said the warning came from "multiple sources," including captured al Qaeda operatives. But they emphasised they still were attempting to determine the credibility of the information.

The advisory said no change was anticipated in the nation's terror alert level. The level remains at "yellow" or an "elevated" risk of attack, where it has generally been since the system began in March last year.

Spokesman Richard Boucher said the State Department would update its current worldwide caution to incorporate the warning of possible hijackings.

The United States has blamed al Qaeda for the September 11, 2001, suicide hijacked airplane attacks that killed about 3,000 people.

In the September 11 attacks, there were five hijackers on each of the two planes that struck the World Trade Center in New York and on the plane that hit the Pentagon. There were four hijackers on the fourth plane that crashed in Pennsylvania.

The advisory warned the plan may involve use of five-man teams and an attempt to seize control of the aircraft shortly after takeoff or before landing.

It said al Qaeda was looking at ways of circumventing airline security and tightened US immigration procedures. Many of the steps were taken after the September 11 attacks.