He said the arrests were made during raids in different parts of the country and that the detainees were being questioned in efforts to capture other al Qaeda members.
"Our forces raided some places in the past two days and captured five terrorists, including foreigners, who are valuable targets," said the official, who spoke on condition of anonymity.
The official would not name the suspects or give their nationalities, and it wasn't clear if any were on the FBI list of most-wanted terrorists. Pakistan's Information Minister Sheikh Rashid Ahmed confirmed the arrests, but refused to share any further details.
Pakistan is a key ally of the United States in its war on terror. In recent weeks, police and security agencies have detained about 30 terror suspects, including Ahmed Khalfan Ghailani, a Tanzanian with a $25 million bounty on his head for his role in the 1998 bombings of U.S. embassies in East Africa.
Ghailani was arrested along with 13 other foreigners during a raid in the eastern Pakistani city of Gujrat on July 25.
Pakistani officials have said that information from Mohammed Naeem Noor Khan, an al Qaeda computer engineer who was captured on July 13 in Lahore, led to Ghailani's arrest and to about a dozen other arrests in London.
Computers from Khan and Ghailani contained photographs of potential targets in the United States and London's Heathrow Airport, as well as pictures of underpasses that run beneath several buildings in London. That suggested al Qaeda might be planning terrorist attacks — although it wasn't clear how recently the photos were taken.
An intelligence official said that the five latest arrests were made on the basis of information gleaned from terror suspects who were captured in recent weeks. He said the five were "definitely al Qaeda men," but declined to say how senior they were.
The latest five arrests came days after Pakistani security officials raided a home in the eastern city of Lahore, capturing two Turkish nationals and an African.
The authorities so far have not revealed the names of the three suspects, although authorities believe that one of the Turks might have been behind a terrorist attack in Turkey.
Another senior government official said he had no details about the attack and whether the Turk was suspected in the suicide bombings blamed on al Qaeda that killed more than 60 people in Istanbul in November.
"So far we only know one of them might have played a role in a terrorist attack in Turkey, but our security agencies are still questioning them," the official said Thursday on condition of anonymity.
The Turkish pair was believed to have moved to Lahore from South Waziristan, a remote tribal region near the border with Afghanistan where Pakistani forces have launched several operations in the recent months to capture al Qaeda suspects.
The African was captured in a different raid.
The official said the Turkish Embassy in the capital, Islamabad, has sought consular access to the two Turks, but "this request is still being examined."
A diplomat at the Turkish Embassy confirmed it was seeking access to the two men and had yet to receive a response from the Pakistani authorities. Speaking on condition of anonymity, the diplomat said the embassy didn't know whether the detainees were involved in any crime in Turkey.
The November attacks in Istanbul targeted two synagogues, a London-based bank and the British Consulate. Turkish officials have charged 69 suspected members of a Turkish al Qaeda cell in the bombings.