U.S. lawmakers are expressing alarm over a Congressional report showing that investigators have been able to use false identities to obtain valid driver's licenses in the United States. They say the report highlights a serious security threat, two years after the terrorist attacks on the United States.

At a hearing before the Senate Finance Committee, officials of the General Accounting Office testified how undercover agents for the congressional watchdog agency obtained driver's licenses in eight states using alias identities.

Robert Cramer, managing director of the GAO's Special Investigations Office, said much of the time government officials did not realize the identity documents were false. In some cases when department of motor vehicles' employees thought the documents looked suspicious, the counterfeits were not confiscated and the applicants were not referred to law enforcement officials.

"Our work reveals that homeland security is vulnerable to identity fraud and, unless action is taken, individuals who intend to cause harm can easily exploit these vulnerabilities," said Mr. Cramer.

Several of the 19 hijackers who crashed planes into the World Trade Center and the Pentagon on September 11, 2001, illegally obtained driver's licenses.

The Finance Committee also heard from Youseff Hmimssa, a Moroccan citizen who described how he bought and sold false identities before September 11.

Hmimssa has pleaded guilty to fraud charges and is awaiting sentencing in Detroit, where he has testified against four men charged with being members of a terrorist "sleeper cell". Three have been convicted of conspiracy to support terrorism or document fraud, and the fourth has been acquitted.

Under questioning from Democratic Senator Max Baucus of Montana, Hmimssa, whose face was blocked from public view, said it was easy to obtain false identity documents both here in the United States and abroad.

"Overseas, it is very easy," admitted Mr. Hmimssa. "You have to have the right connection. You can get any passport: French, Italian, or any passport from Europe."

[It's] the same thing [in the United States], he said. "You just have to have the right connections. You can get a birth certificate, social security card from someone who is not using it, or someone who is dead."

Committee Chairman Charles Grassley, an Iowa Republican, expressed serious concern over what he had heard. "This has been a very alarming set of testimony we have had," he commented. "I think it shows we are still too vulnerable to document and identity fraud, which in turn, means that we still are vulnerable to terrorism."

Homeland Security Under Secretary Asa Hutchison said law enforcement agencies are addressing the problem. "We are certainly encouraging more restrictive use of state drivers' licenses, more security features, and we are trying to develop our capability to have more security features as these are presented at our borders," he said.

Mr. Hutchison said part of the problem is that the states offer some 240 different types of driver's licenses. He said law enforcement agencies are working with motor vehicle departments to develop uniform standards for such licenses.