ISLAMABAD - Pakistan said on Friday it had arrested a man it described as an al Qaeda operative who had played a key role in a plot British police said they had foiled to blow up transatlantic airliners.

"He is a British citizen of Pakistani origin. He is an al Qaeda operative with linkages in Afghanistan," Interior Minister Aftab Ahmed Khan Sherpao told Reuters.

Sherpao said the arrest of the man, identified as Rashid Rauf, had led to a wave of arrests in Britain that headed off the alleged plot to blow up as many as 10 aircraft flying from Britain to the United States.

A senior government official earlier said that two Britons of Pakistani descent along with five other suspects had been arrested in Pakistan as part of a coordinated operation to foil the plot. The name of the other Briton has not been released.

The official, who spoke on condition of anonymity, said the two Britons were key catches, and had been arrested last week.

Investigators were still establishing the identities of the other five people arrested, but they appeared to be less important, he added.

A Foreign Ministry statement said: "A key person arrested is British national Rashid Rauf. There are indications of (an) Afghanistan-based al Qaeda connection."

British authorities have named a Tayib Rauf as one of 24 suspects arrested this week in Britain. It was not clear whether he and Rashid Rauf are related.

Pakistan said the alleged airliner plot was thwarted after active coordination between Pakistani, British and U.S. intelligence agencies.

British Prime Minister Tony Blair phoned Pakistani President Pervez Musharraf, a crucial ally in the U.S.-led war on terrorism, and thanked him for Islamabad's help in the case, the Foreign Ministry said.

SIMILARITIES TO 9/11

U.S. officials have said would-be suicide bombers were just days away from simultaneous attacks that one British police chief said would have amounted to "mass murder on an unimaginable scale."

Officials pointed to similarities to the September 11, 2001 hijacking of U.S. airliners for attacks on New York and Washington and "Operation Bojinka," a plan never carried out, to blow up passenger planes over the Pacific Ocean in 1995.

A key figure in both was Khalid Sheikh Mohammad, the al Qaeda operations planner arrested in Pakistan in 2003.

Several al Qaeda leaders, including Osama bin Laden and his deputy Ayman al-Zawahri, are believed to be hiding in Pakistan or across the border in Afghanistan. The militant network has forged links with some Pakistani groups.

At least two of the British Muslims involved in bomb attacks on London underground trains and a bus that killed 52 people in July last year had visited Pakistan months earlier, raising suspicions they had ties to militants in the country.

Pakistan has arrested hundreds of people it says are al Qaeda members since joining the U.S.-led global war against terrorism that followed the September 11 attacks.