WASHINGTON - Yesterday, a federal grand jury charged alleged shoe bomber Richard Reid with being an al-Qaida trained terrorist in an indictment Attorney General John Ashcroft hailed as fresh proof of the government's ability to prosecute terrorists.

Ashcroft said the charges "alert us to a clear, unmistakable threat that al-Qaida could attack the United States again."

The attorney general discussed the charges shortly after a federal grand jury in Boston handed up a nine-count indictment, saying, "We must be prepared. We must be ready. We must be vigilant."

The indictment alleges that Reid attempted to kill the passengers on American Airlines Flight 63 from Paris to Miami on Dec. 22.

"Richard Reid did attempt to use a weapon of mass destruction, consisting of an explosive bomb placed in each of his shoes," against Americans, said the 12-page indictment.

Ashcroft credited passengers and crew on that flight with stopping Reid from detonating the shoe bomb and bringing down the plane. "Our trust in the common sense of people who act in the face of terrorism was vindicated," he said. He said yesterday's indictment showed the wisdom of national alerts the government issued on three occasions prior to the Flight 13 incident.

Yesterday's indictment said Reid "received training from al-Qaida in Afghanistan."

In addition to attempted use of a weapon of mass destruction and attempted murder and attempted homicide, Reid was charged with placing an explosive device on an aircraft, interfering with a flight crew, using a destructive device during a crime of violence and attempted wrecking of a mass transportation vehicle.

He also was charged with attempted wrecking of a mass transportation vehicle, a new charge created by Congress in an anti-terrorism bill enacted in the wake of the Sept. 11 attacks on New York and Washington.

"Our ability to prosecute terrorists has been greatly enhanced by the U.S.A. Patriot Act," Ashcroft said.

Reid "did place on that aircraft explosive devices contained in the footwear he was then wearing," the indictment said, referring to the American flight.

Ashcroft said if convicted on the charges brought against him, Reid could be sentenced to five life terms.

There were 183 passengers and 14 crew members on the flight, which was escorted into Boston's Logan Airport.

On the charge of interfering with the flight crew, the indictment said Reid assaulted and intimidated flight attendants Hermis Moutardier and Christina Jones.

Reid's court-appointed defense attorney, Tamar Birckhead, did not immediately return a call for comment. Reid has been held since Dec. 22 in Plymouth, Mass.

A U.S. official speaking on condition of anonymity had said earlier that Reid may be an al-Qaida target scout known as "Abdul Ra'uff." Reid's travels match those of an al-Qaida operative known as Abdul Ra'uff, which are listed in a computer obtained in Afghanistan by a Wall Street Journal reporter. The similarities in the two's movements in Europe and the Middle East have led investigators to suspect they are the same person.

Reid is accused of trying to blow up the American Airlines flight on Dec. 22. He was overpowered by flight attendants and passengers as he allegedly tried to light a fuse protruding from his sneakers.

Reid converted to Islam while in prison for petty crimes. He later worshipped at the same south London mosque as Zacarias Moussaoui, charged with conspiracy in the Sept. 11 terrorist attacks.

An Israeli official, speaking on condition of anonymity, said it was possible that Reid was gathering intelligence for large-scale terrorist attacks in Tel Aviv and other cities and was working for al-Qaida.

Israeli officials have generally been tightlipped about Reid since he was arrested and accused of trying to blow up the American Airlines flight. Earlier this week, a U.S. military official, speaking on condition of anonymity, said one of the al-Qaida prisoners at Guantanamo Bay had identified Reid as someone he had trained with at camp run by al-Qaida.

Reid had boarded an El Al flight to Tel Aviv on July 7. He spent five days in Israel, before traveling to Egypt via the Rafah border crossing at the southern end of the Gaza Strip. From Egypt, Reid apparently returned to Europe on a commercial flight, Israeli reports said.