FBI joins interrogation of prime suspect

An international tug of war broke out yesterday as American and Pakistani investigators questioned one of the most senior al-Qa'ida suspects to be captured since the 11 September attacks on New York and Washington last year.

Ramzi Binalshibh, who was arrested after a three-hour gun battle in the Pakistani city of Karachi on Wednesday, the anniversary of the attacks, is considered one of the chief planners and organisers of the operation. If he had not been denied a US visa, it is believed, he would have piloted one of the hijacked airliners flown into the World Trade Centre and the Pentagon.

According to a senior Pakistani policeman, Mr Binalshibh was traced to a three-storey apartment building in Karachi when FBI agents intercepted a satellite phone call from the building. A satphone intercept in Pakistan is also thought to have led to the arrest in March of Abu Zubeida, the highest member of the al-Qa'ida leadership in custody.

Pakistan's President Pervez Musharraf said at the UN in New York on Friday that a total of 10 foreigners – one Egyptian, one Saudi and eight Yemenis – had been captured in Karachi. That implied that Khalid Shaikh Mohammed, a Kuwaiti who is the alleged mastermind of 11 September, remains at large. Last week the Al-Jazeera satellite channel broadcast an interview with Mr Mohammed and Mr Binalshibh which it said had been recorded in Pakistan three months ago.

But Mr Binalshibh is a significant prize. Yesterday Germany's interior minister, Otto Schily, said he would seek the extradition of the 30-year-old Yemeni to Germany, where he shared a room with Mohamed Atta, the leader of the 11 September hijackers. The Pakistani authorities scotched rumours that he had been sent immediately to the US, saying FBI investigators were taking part in his interrogation.

A senior army officer told Reuters he visited the interrogation centre where the captives were being held, and saw two prisoners whom he did not identify. They were undergoing interrogation while blindfolded and seated with their hands shackled to the arms of their chairs. One of the prisoners was "very tough", said the officer, and answered probing questions only with the words: "My name is Abdullah."

It also emerged yesterday that the American authorities have arrested five men believed to be part of a terrorist cell in a quiet suburb of Buffalo, New York. FBI agents raided several locations on Friday evening in the Buffalo suburb of Lackawanna – 300 miles north-west of New York City – arresting five Americans of Yemeni descent on suspicion they were part of a terrorist cell operating on US soil.