WASHINGTON/KARACHI, 16 September — The United States has sought custody of Ramzi Binalshibh who was arrested in Pakistan last week. Appearing on the "Fox News Sunday" program, US President George W. Bush’s national security adviser, Condoleezza Rice, said US officials were eager to question Binalshibh, a key Al-Qaeda operative, to determine what he knew about last year’s attacks on America that killed more than 3,000 people. "We certainly want custody of him," said Rice.

Binalshibh was arrested in Karachi on the anniversary of the attacks he is accused of helping to plan. He reportedly had hoped to become the 20th hijacker and roomed with Sept. 11 mastermind Mohammed Atta.

He is also wanted by Germany for his alleged role in the hijacked airliner attacks, and is one of the most important Al-Qaeda members to be taken into custody in the past year.

"We certainly want to be able to find out what he knows," Rice said, adding that the United States would "work with the Pakistani officials" to obtain his custody.

In Pakistan, officials said they were prepared to send Binalshibh and 10 others arrested with him abroad for trial but that no decision had been reached on where they would go. But a German official said yesterday that Berlin would not pursue extradition and that US efforts on Binalshibh took precedence.

Talking about Binalshibh, Secretary of State Colin Powell told CNN: "I think he’s a pretty big fish. I mean, this is perhaps within the circle of those who were responsible for 9/11."

Binalshibh has been identified as an unindicted co-conspirator in the charges against Zacarias Moussaoui, the only person charged in the Sept. 11 attacks who is facing trial in Alexandria, Virginia. For purposes of extradition, US officials could charge Binalshibh in the United States with criminal violations, or he could be turned over as an enemy combatant.

US authorities believe Binalshibh had close ties with prominent Al-Qaeda leader Khaled Sheikh Mohammad, who is considered a potential successor to Osama Bin Laden and his senior lieutenant, Ayman Al-Zawahri, if they died.

"We know he’s been operationally involved with Khaled Sheikh Mohammad since 9/11 in discussing potential future attacks," a US official said. "He’s closely associated with many of the 9/11 hijackers and knows who else they would have associated with, who else is still out there, how they were recruited, how they were employed," the official said.

In Pakistan, Binalshibh and 10 other suspects are being held in a secret, high-security location. "They are being interrogated to retrieve maximum possible information about other Al-Qaeda suspects in Pakistan," an army source, who asked not to be identified, said.

The source said the arrested men were being kept blindfolded and handcuffed during questioning, with the two leading suspects held separately from their colleagues. "Most of the time it’s FBI officials who are interrogating them," he added.

US and Pakistani agents who are interrogating the suspects have seized evidence in their hunt for more operatives, a Pakistani intelligence officer said. He said the investigators returned Saturday night to two bungalows where some of the suspects were arrested last week. "The most vital thing they got is a telephone index and an office file containing printouts of some e-mails," the officer said.

He said the FBI is firmly in charge of the investigation. "The Pakistani intelligence officers have been asked to hand over all information concerning the case to the FBI and work in accordance with guidelines they receive from the Americans," the officer said.

"The FBI officers are interrogating the suspects according to their methods and not allowing Pakistani intelligence to interfere," the officer said.

Pakistani police said US agents had traced Binalshibh to a three-story building in an upmarket district of Karachi thanks to a satellite phone call. Security and intelligence agents met armed resistance when they raided the building on Wednesday and had to call in hundreds of police to help flush the men out.

Pakistan’s Interior Minister Moinuddin Haider said one of the dead men might have been Egyptian but said others killed or arrested were Yemeni. At first police believed Khalid Sheikh Mohammad was among the two killed in the gunbattle, but intelligence officers later said the identification was wrong. But Khalid is believed to be still in Karachi.