WASHINGTON (AP) — The FBI is seeking nearly 400 people for questioning in the terrorist attacks probe while federal prosecutors build a criminal case involving identification cards for five of the now-dead hijackers. One man has been charged.

As the investigation proceeded on several fronts Monday, a Florida bank president said he had been told that one of the men suspected in the Sept. 11 hijackings of four airliners tried to get a loan from the U.S. Agriculture Department to buy a crop dusting plane.

Attorney General John Ashcroft told Congress the FBI had gathered information raising fears that crop dusters could be used in a biological or chemical attack. At the FBI's request, the planes were grounded Sunday and Monday. The grounding was lifted early Tuesday.

In the criminal case, the government said Herbert Villalobos accompanied Abdul Aziz Al Omari and Ahmed Saleh Al Ghamdi to a lawyer's office in Virginia on Aug. 2 to help the two suspected hijackers obtain state identity cards.

When shown photos of the hijackers by the FBI, Villalobos recognized three other suspects "believed to have commandeered American Airlines Flight 77" from Washington Dulles International Airport that crashed into the Pentagon, according to court documents. Villalobos said Hani Hanjour, Salem Al Hazmi and Majed Moqed were at the Arlington, Va., office of the state Department of Motor Vehicles on Aug. 2, just as Al Omari and Al Ghamdi were.

"Virginia DMV records ... show that all five men did in fact conduct various transactions relating to Virginia identification cards at the Arlington DMV," said a seven-page affidavit by an FBI agent.

The affidavit did not say whether the five used the IDs to become ticketed passengers aboard the doomed flights, which also crashed in New York City and a field in Pennsylvania.

The FBI says Al Omari was aboard American Airlines Flight 11 that struck the north tower of the World Trade Center.

Al Ghamdi was aboard United Flight 175 that hit the trade center's south tower. Villalobos was charged with unlawfully signing a Virginia residency form for Al Omari.

More than 6,000 people are missing and presumed dead from the attacks, in which Saudi exile Osama bin Laden has been named the leading suspect. Ashcroft said 352 people have been arrested or detained in the investigation and 392 others who "we think ... have information that could be helpful" were being sought for questioning.

There was concern over the potential for further attacks.

Robert Epling of Community Bank of Florida said he's been told that Mohamed Atta, one of the suspected hijackers, sought a USDA loan for a crop duster. The USDA is a tenant in the bank, which checked its files about Atta at the request of the FBI.

"We understand he was turned down" at the USDA "and they referred him to us," said Epling. A loan officer at the bank remembered a phone call from someone inquiring about crop dusters, an unusual request because there are so few of the planes left in the area, Epling said. Nothing came of the inquiry from the unnamed person.

James Lester, an employee of South Florida Crop Care in Belle Glade, told the FBI that Atta was among the men who in groups of two or three visited the crop dusting firm nearly every weekend for six or eight weeks before the attacks.

Atta was a persistent questioner and "I recognized him because he stayed on my feet all the time. I just about had to push him away from me," Lester said.

Crop dusters weren't the only concern.

In Michigan the president of a truck driving school confirmed two men arrested last week had attended the school and one of them obtained a permit to transport hazardous materials.

Karim Koubriti, 23, and Ahmed Hannan, 33, taken into custody Sept. 17, attended the U.S. Truck Driver Training School in Detroit this summer, said the school's president, Joseph LaBarge. Koubriti passed the state commercial drivers license exam on Aug. 22 and received a permit to transport hazardous materials. Hannan failed the road test, LaBarge said.

Koubriti and Hannan were living in the same Detroit residence as an earlier tenant who also is under arrest in the probe, Nabil Al-Marabh. Al-Marabh also was certified to transport hazardous materials and is licensed to drive trucks and other large vehicles.

Al-Marabh, a former Boston cab driver, was transferred to New York following four days of questioning, FBI spokeswoman Virginia Wright said.