The government's new central database for terrorism suspects is missing names, and those omissions heighten the risk a terrorist could go undetected in the United States, the Justice Department's inspector general says.

In addition, in one instance last year, someone on the government's no-fly list was allowed to board a domestic airline flight because of poor coordination between the FBI-run Terrorist Screening Center and other law enforcement agencies, Inspector General Glenn A. Fine said yesterday.

"There is little room for error because a single name omitted from the [database] could result in a suspected terrorist successfully applying for a visa, being admitted to the United States, or failing to be identified when stopped for a traffic violation," Fine wrote in a 184-page report on an audit that was conducted between April and November 2004.

Fine also found some names that were mistakenly included in the database. Still, he praised the ambitious effort to merge about a dozen terrorist watch lists from nine agencies. He called it a "significant accomplishment" that the consolidated list was up and running a few months after President Bush created the center in a September 2003 order.

He noted that the quality of the work has improved as officials solved some problems and refined the database.

Donna A. Bucella, the center's director, said problems identified by Fine have been corrected and noted that she had requested the audit.

"The consolidated database is up to date and contains all known or suspected terrorists," Bucella said. The center's round-the-clock operation has made more than 16,000 matches when authorities called in to see if an individual was on the watch list, she said.

The center was designed as a one-stop shop that any government official -- a Customs agent at an airport or a state trooper watching for speeders -- can consult to check the name of someone who has been screened or stopped.

The merged databases include the Transportation Security Administration's no-fly list of terrorist suspects barred from air travel; the State Department's massive Tipoff list, which is checked when visas are issued; and the FBI's National Crime Information Center list of convicted felons, fugitives and other wanted people used by police nationwide.

Some lawmakers had criticized the Bush administration for taking too long to get the database started. Civil libertarians have pointed out potential danger in duplicate or incorrect names causing trouble for innocent people.

Fine raised concerns about missing information after his auditors determined the consolidated database did not contain names that should have been on the watch list. Some information on publicly known terrorists was missing, as was information on other people that authorities could use to assess the threat posed in an encounter, he said.

The system also has mistakenly identified people as being in the database, he said. He added that better procedures are needed for dealing with misidentifications.

After reviewing a small sample of files, auditors also discovered several instances in which there were duplicate records for the same person, but with important differences. One record identified a person as providing money, weapons and other support to terrorists. The duplicate record said that person was likely to engage in terrorism if allowed to enter the United States.

Such duplication can be time-consuming, or worse, Fine said, when someone calls the screening center to check a name.

"The call screener can mistakenly rely on one record while a second, more complete, record may be ignored," he said. "This can result in important information being missed."