LONDON, Aug 5 (AFP) - British police were Thursday quizzing 12 terrorist suspects, reportedly including a top Al-Qaeda suspect, amid suggestions that a recent wave of arrests around the world has highlighted the network's global reach.
Separately, Italian authorities raised the security alert at airports and Britain's top naval officer warned of a potential threat to shipping.
The man, identified to AFP by Pakistani intelligence officials as Abu Eisa Al Hindi, was one of 13 people detained late Tuesday in Britain.
One was later released, but the other 12 remain in custody. British police have refused to give any further information.
The detentions follow a series of arrests in Pakistan and raised security alerts over the weekend in the United States.
The New York Times, citing US officials, said the heightened security alert in the cities of New York, Newark and Washington was linked to the British arrests and was part of a campaign to disrupt terrorist operations worldwide.
In Islamabad, Interior Minister Faisal Saleh Hayat said Pakistani security forces had captured almost 20 Al-Qaeda suspects in the past three weeks.
"Some of them are Pakistanis and some are foreigners. We have extracted a wealth of information from all those who have been arrested," he said.
"These terrorists, they have their network spread out all over the world."
Computer files taken from suspected operatives Naeem Noor Khan, a Pakistani computer expert, and Ahmed Khalfan Ghailani, a Tanzanian indicted over his alleged role in the 1998 US embassy bombings in east Africa, contributed to the heightened US alerts because they contained detailed surveillance photos and records of key financial institutions.
A Pakistani security official told AFP Wednesday that Khan, 25, alias Abu Talha, "was involved in planning for attacks at Heathrow airport, London, some time ago and was wanted by the US government."
Pakistani authorities were interrogating the detainees and would not hand them over to other countries until their own probe was completed, Hayat said.
Two South Africans allegedly plotting to attack sites in Johannesburg and a Nigerian man who was carrying coded messages were also arrested.
A senior US intelligence official told the New York Times that "there are activities going on right now in this country (the United States) and overseas that are capitalizing on the information that has been uncovered."
He refused to provide details that might compromise the effort.
Nevertheless, while the British arrests were "important," a senior cabinet minister said, there was no specific terrorist threat to Britain.
"If we had evidence of a specific threat then we would tell everybody," the Minister for Wales, Peter Hain, told BBC radio.
Meanwhile, Italy said that it had stepped up security at all the country's international airports after threats from a group claiming to be linked to the Al-Qaeda network.
The alert level at Rome-Fiumicino airport and others handling international flights had been raised from "Bravo," for a significant risk, to "Charlie," which signifies heightened risk, airport officials said.
A group calling itself "Abu Hafs al-Masri Brigades - Al-Qaeda Organization" threatened in a statement dated July 31 to attack Italians everywhere unless Rome pulls its 3,000 troops out of Iraq within 15 days.
Security has been increased in particular for airline companies considered most at risk, including British Airways, American airlines Delta, Continental and US Airways and Israeli flag carrier El Al.
Separately, Britain's top naval officer, Admiral Sir Alan West, said that Al-Qaeda and other groups had realised the importance of global maritime trade and could launch attacks against merchant ships.
"We have got an underlying level of intelligence which shows there is a threat," he said in an interview with the shipping newspaper Lloyd's List.