Pakistani officials say a key al-Qaeda suspect caught near the border with Afghanistan this week is likely to have crucial information about the network.
Interior Minister Faisal Saleh Hayat told reporters that Adil al-Jazeeri - an Algerian national living in Peshawar, in the North-West Frontier Province - would be privy to many details about al-Qaeda operations.
Some leading al-Qaeda suspects have been captured in Pakistan
Mr al-Jazeeri, who is being questioned by police, was detained in the Hayatabad district of the city after the interrogation of a Tunisian, Abu Naseem, who was arrested earlier.
The arrests were part of a continuing hunt for suspected al-Qaeda activists believed to be hiding in Pakistan.
The two were among five men - believed to be Arabs and Afghans - detained for suspected al-Qaeda links.
Series of arrests
"Being a facilitator [al-Jazeeri] is privy to certain activities which normal operatives do not have. He must have a lot of information," Mr Hayat told AFP news agency.
It is the latest in a series of arrests by Pakistani officials of suspected al-Qaeda activists.
Last month security forces arrested Haffan al-Hasham, who was believed to be involved in al-Qaeda's communications network.
Pakistani security personnel accompanied by American FBI agents made the arrest near the southern city of Karachi
April saw the arrest of two suspected al-Qaeda operatives who were believed to be part of a group that was under investigation when a member of Pakistan's intelligence services (ISI) was killed in March.
This was the first killing of an intelligence official in the area since operations to flush out suspected al-Qaeda or Taleban militants began in late 2001.
The ISI has captured more than 450 al-Qaeda suspects since the fall of Afghanistan's Taleban government in late 2001.