Intelligence officials on Friday said the Yemeni national, identified as Shaikh Yusuf and the two Pakistanis were arrested more than 60km north of Karachi.

Security forces seized documents, a satellite telephone and some weapons.

Many al-Qaida members and their Taliban supporters have fled to Pakistan to escape a crackdown by the US-led forces in neighbouring Afghanistan.

Pakistani security forces have arrested nearly 600 al-Qaida and Taliban suspects and continue to hunt them in the mountainous region bordering Afghanistan as well as in major cities.