Security officials in Yemen said Saturday air strikes in the southern part of the country have killed at least 10 suspected al-Qaida militants.

Witnesses say they believe the raids late Friday were carried out by U.S. aircraft.

Militants expanded their base in Yemen during the months of turmoil that eventually resulted in the ouster of president Ali Abdullah Saleh, who formally stepped down last month.

The U.S. and Saudi Arabia – Yemen's neighbor – have been concerned about the expansion of al-Qaida in Yemen.