WASHINGTON, Aug 4: The US administration continues to fortify Washington against possible terror threats despite criticism that the terror alert is based on dated information.

Capital police chief Terrance Gainer and Senate Sergeant-at-Arms William Pickle have announced a plan to further tighten security arrangements already being criticized by the city administration as excessive.

With armed policemen riding trains in full combat gear and makeshift police-check posts erected at sensitive crossroads, Washington looks like a besieged city. Police officers carrying automatic weapons patrol streets around Capitol Hill.

Police also closed a major thoroughfare on Capitol Hill to set up 14 vehicle checkpoints, creating a huge security perimeter around the Hill. Checkpoints were also set up near the World Bank and the International Monetary Fund buildings, five of the two possible targets for an Al Qaeda attack. Three other targets are in New York.

Squads of officers from different agencies are patrolling streets around the two financial buildings and the areas near the White House and the State Department. Police with bomb-sniffing dogs were also deployed at some metro stations in downtown Washington.

In neighbouring Virginia, thousands of police, fire fighters, members of the military, state officials and homeland security experts are preparing for a major anti-terrorism drill later this week.

The new security plan for the city includes training officers around the Capitol to shoot a suspected suicide bomber in the head, creating a 'virtual fence' around Capitol Hill, allowing officers to search every person entering the area, and to restrict traffic in sensitive places.

Israeli counter-terrorism experts and bomb technicians have been hired to train officers. These strict security arrangements have irked Washington's mayor and some US lawmakers.