By JOHN J. LUMPKIN, Associated Press Writer

WASHINGTON (AP) - The tracking of Jose Padilla's alleged "dirty bomb" plot to Pakistan adds to growing evidence that some members of al-Qaida have begun using Pakistan as a base to plan international terrorist operations, U.S. officials said Wednesday.

Padilla, the American citizen being held by the military as an enemy combatant, is accused of being part of a plot to detonate a radiological weapon in the United States.

He worked out of Lahore, Pakistan, and twice met with senior al-Qaida operatives in Karachi in March, officials said. During the meetings, Padilla and the others are alleged to have discussed the radiological weapon plot, as well as proposals to bomb gas stations and hotel rooms.

Authorities in an unspecified foreign country are also questioning at least one of Padilla's alleged accomplices from Lahore, U.S. officials said, speaking on condition of anonymity. Officials declined to elaborate.

Padilla is alleged to have traveled with one of Osama bin Laden ( news - web sites)'s chief lieutenants, Abu Zubaydah, from Afghanistan ( news - web sites) to Pakistan. Abu Zubaydah was captured on March 28 in the industrial city of Faisalabad.

After the fall of the Taliban in Afghanistan last year, the al-Qaida scattered, with some small pockets retaining enough cohesion to oppose U.S. and anti-Taliban troops in some of the Afghanistan provinces along the border with Pakistan.

But numerous al-Qaida members have fled into Pakistan, officials said. Some are in the tribal belt, a largely autonomous region along the Afghan border. Small numbers of U.S. operatives are looking for them in a largely secret operation.

Far in the north, a few non-Pakistani al-Qaida supporters are believed to have sought refuge in the Kashmir ( news - web sites) region dividing India and Pakistan, U.S. officials said. Some of the Pakistani militants in Kashmir have long-standing ties to al-Qaida, and some trained in bin Laden's camps in Afghanistan.

Defense Secretary Donald H. Rumsfeld said Wednesday that the al-Qaida may be operating in Kashmir.

But there is no evidence the cross-border violence in Kashmir is an attempt by al-Qaida's Arab leaders to start a war between India and Pakistan, officials said. Instead, it appears that Pakistanis in the region are acting on their own.

Other al-Qaida members ended up in the cities, like Abu Zubaydah and the unidentified senior operatives Padilla is said to have met with in Karachi, on the southern coast of Pakistan.

Officials said the al-Qaida network's capability to conduct terrorist attacks internationally remains intact.

Padilla's travels put him on four continents in less than a month.

He left Karachi in early April, and briefly traveled to Zurich, Switzerland, before going to Cairo, Egypt. He spent a month there, went to Zurich again, and on May 8 flew to Chicago, where he was arrested by the FBI ( news - web sites), officials said. U.S. agents had trailed him for some of his journeys.

Officials said further he was probably flying to the United States to scout targets for al-Qaida. The plot to detonate a dirty bomb was in its planning stages, but probably would have targeted Washington, they said. Operatives planned to steal the radioactive material needed for the weapon from research or industrial sites in the United States, rather than smuggle it into the country, officials said.

CIA ( news - web sites) Director George J. Tenet, whose agency was instrumental in discovering the dirty bomb plot, briefed the House Intelligence Committee on Wednesday on Padilla, officials said.

Since his capture, Padilla, a former gang member from Chicago, has been uncooperative with U.S. interrogators, officials said.

Court papers made public Wednesday sought Padilla's immediate release on grounds that the government had violated his rights by detaining him without formal charges.

"The evidence linking Padilla to the alleged 'dirty bomb' plot is weak at best," defense attorney Donna Newman wrote in demanding justification from the government for his continued detention.

Newman said on CNN that she is not being allowed to contact Padilla.

"A U.S. citizen is being detained, he is being questioned and interrogated because the administration has determined, decided, judge and jury, that this man is guilty, but they refuse to charge him with anything," Newman said.

Padilla also had been subpoenaed to testify before a New York grand jury investigating the Sept. 11 terror attacks, and one person familiar with that situation said Padilla had refused to testify.

Padilla's mother, Estela Ortega, testified two weeks ago, according to her lawyer, Victor Olds.

In addition, in Islamabad, Pakistan, a senior Pakistani intelligence official said a man named Benjamin Ahmed Mohammed is being held and questioned by FBI agents for his connection to Padilla. The official did not know Mohammed's nationality. U.S. officials said that's not the name of Padilla's alleged accomplice from Lahore.

In a related development, U.S. and German officials said they have identified a German citizen of Syrian origin who recruited Mohammed Atta and other Sept. 11 hijackers into al-Qaida, The Washington Post reported in its Wednesday editions.

The suspect, Mohammed Haydar Zammar, has been missing since October, but an official told the Post the Germans suspect he is in U.S. custody or being detained in another country at the United States' request.

CIA officials would not comment on that report.