Pakistan has arrested a suspected member of al Qaeda with a multi-million dollar price on his head and several others.
Arrests over the last three days in Pakistan follow on from an earlier sweep for militants which led to information of a possible attack in the United States and a subsequent rise in the US state of alert.
"We have arrested in the past 24 hours from Punjab another two people of African origin who in our view have links to al Qaeda," Interior Minister Mr Faisal Saleh Hayat said.
"Before that another person was arrested who has a multi-million dollar bounty on his head," the minister added.
The crackdown on militants in Pakistan has apparently gathered pace since the capture of a computer engineer who acted as an e-mail postman for the groups by distributing coded messages. The New York Timessaid he was arrested in mid-July.
US officials say information from that arrest, and from the later capture of senior al Qaeda member Ahmed Khalfan Ghailani, prompted them to issue a high alert warning to financial institutions in Washington, New York and New Jersey.
One of those arrested was a policeman suspected of passing information to al Qaeda plotters planning to assassinate the Chief Minister of Punjab province, Chaudhary Pervez Elahi.
One of the foreigners was arrested at a bus stop in the town of Hafizabad in Punjab province. Intelligence sources named him as Jummah Ibrahim and said he was from Sierra Leone.
The sources said the suspect had first claimed he was from Yemen and then Egypt.
The other foreigner was an al Qaeda suspect arrested along with two Pakistanis travelling to the eastern city of Lahore in Punjab from the town of Sheikupura on Monday night.
One intelligence official said the Pakistanis belonged to Lashkar-e-Jhangvi, a local Sunni Muslim militant group, and that one had a bounty of 500,000 rupees on his head.
Two AK-47 rifles, 150 rounds of ammunition, half a dozen grenades and several documents were found in their vehicle.
A week ago, Pakistani security forces caught Tanzanian-born Ghailani, who carried a $5 million reward on his head, and 13 others following a firefight in Gujarat, a town in Punjab which is 175 kilometres southeast of Islamabad.
Ghailani was wanted by the United States for his suspected role in the 1998 bombings of two US embassies in East Africa that killed 224 people.
Intelligence sources say they also seized a computer and more than a hundred disks when they caught him.
The Washington Post however said the initial breakthrough in Pakistan came from the capture of Musaad Aruchi, a nephew of September 11, 2001 attacks mastermind Khalid Sheikh Mohammed, in Karachi on June 12.
The newspaper quoted Pakistani intelligence sources as saying that arrest gave them access to a host of documents, e-mail addresses and cell-phone text messages that gave them clues to an al Qaeda plan to strike at targets in New York and Washington.
According to Pakistani officials, Aruchi was both a nephew of Khalid Sheik Mohammad and a cousin of Ramzi Ahmed Yousef, who carried out a 1993 attack on the World Trade Center.
Mohammad was arrested in the northern Pakistan city of Rawalpindi in March last year, while Yousef is serving a life sentence in the United States.