Yemen's foreign minister estimates there are some 400 al-Qaida fighters active in the country.
Abu Bakr al-Qirbi says the militants "seek to cause chaos and destruction." He told the al-Hayat daily on Sunday that Saudi nationals are among the active fighters.
Al-Qaida's Yemeni and Saudi offshoots joined forces last year to form al-Qaida in the Arabian Peninsula, which is based in Yemen.
Since then, the terror group has stepped up attacks in the capital, San'a, and in the largely lawless countryside.
Meanwhile, a security official said 19 al-Qaida suspects have been released after months in detention because of a lack of evidence. He said three of them originally were picked up in Iraq.
The official spoke on condition of anonymity because he wasn't authorized to speak to the media.