Pakistani security officials say they have arrested a French man accused of being a prominent al-Qa'ida militant.
The officials named the man as Naamen Meziche. Western media reports have described Meziche as an al-Qa'ida operative with links to European jihadi groups believed to have been living until now in either Pakistan or Iran.
The statement said he was arrested on the border of Pakistan and Iran but no mention was made of when the arrest took place.
Meziche was captured in a raid near the border with Iran, officials said, without specifying when it happened.
He is being questioned by Pakistani intelligence agents.
The officials said Meziche was a close associate of Younis al-Mauritani, who Pakistani security forces arrested in September last year in a joint operation with the CIA. That arrest took place in Baluchistan, which borders Iran.
US officials said al-Mauritani was believed to have been plotting attacks in Europe. It is unclear where he is being held.
Baluchistan borders Afghanistan to the north east and has been a hotbed of militant activity.
The latest arrest highlights the Pakistani security forces' key role in the anti-al-Qa'ida campaign, even as the US and Pakistan are going through one of the rockiest stages in their relationship since the September 11 attacks in the US.
CNN and the Wall Street Journal said Meziche was a friend of Mohammed Atta, who piloted American Airlines Flight 11 into the World Trade Centre in the 9/11 attacks, although Meziche does not appear to have had any operational role in the attacks.