Washington: Ahead of the second anniversary of September 11 terror attacks, US is bracing up against al-Qaida's plans for multiple strikes on American targets using tactics like car bombs, hijacking airlines from other countries and using men dressed as women to avoid scrutiny.

"We remain concerned about al-Qaida's continued efforts to plan multiple attacks against the US and its interests overseas... We do know that operatives still at large view attacks on US territory as a priority," said an advisory by the Department of Homeland Security.

Terrorists might try to hijack airliners in Mexico or Canada that can be flown into US targets, it said.

The advisory suggested that terrorists could target relatively unprotected targets in US like apartment complexes, gas stations and restaurants. VIPs could also be targetted.

"Arrests over the past several months have delayed or even disrupted some plans," it added.

However, a spokesman of the Department, Gordon Johndre, said "the intelligence information we have is not specific enough" to raise the threat alert level from the current yellow for "elevated risk" to orange for "high risk" because "the intelligence we have is not specific enough to do that".

The alarm was sounded because of several factors - the approaching anniversary of the September 11, 2001 terror attacks; an alarming rise in intelligence indicating that al-Qaida operatives are scouting an array of targets; and recent terrorist attacks in Saudi Arabia, Indonesia and Iraq.

PTI