By Zaffar Abbas BBC correspondent in Islamabad

Pakistan's Foreign Ministry has confirmed that security agencies have arrested five Sudanese nationals who were taking training in flying aircraft.

The men received training at a private club in the north-western city of Peshawar and are being questioned for any possible links with al-Qaeda.

Pakistan has many al-Qaeda sympathisers

This is the second such arrest of foreign nationals in one week. On Wednesday, Pakistani authorities, with the help of the American FBI, rounded up more than 50 suspected al-Qaeda members.

Most of them were of Arab and Afghan origin, and were picked up from the city of Faisalabad in Punjab province.

The latest arrests in Peshawar have been carried out on the basis of information provided by the American FBI.

Suspicious flyers

The US agency is now getting intensely involved in Pakistan in tracking down suspected al-Qaeda members.

Religious tensions remain high

A Foreign Ministry spokesman in Islamabad said the five people arrested over the weekend are citizens of Sudan but declined to give more details.

Security officials said these people had come to Pakistan a couple of months ago on valid travel documents to attend the flying course.

There are no specific charges against them, so far.

Officials say the action has been taken against the backdrop of the use of passenger aircraft in the terrorist attacks in the USA on 11 September.

Criticism of US

Last week, the FBI supervised a highly-organised raid in the city of Faisalabad to arrest more than 50 people.

A member of the US-Pakistani joint intelligence team is interrogating them as one of them is believed to be Abu Zubaydah, a close aide to Osama bin Laden.

There has been growing criticism in Pakistan of the FBI's involvement in the country's internal security affairs.

But the Foreign Ministry spokesman says the co-operation is only limited to the sharing of intelligence in dealing with the al-Qaeda network.