Yemeni security officials say airstrikes on Islamist militants in the southern province of Abyan have killed at least three fighters.

The officials say the airstrikes happened before dawn Thursday, hitting a police station seized by the militants earlier this year in the town of Wudiya.

There were conflicting reports about whether U.S. or Yemeni warplanes bombed the station. The United States provides military aid to Yemen in exchange for Yemeni cooperation in fighting al-Qaida militants based in lawless parts of the impoverished country.

Islamist militants, some linked to al-Qaida, have taken control of several towns in southern Yemen in recent months, as government forces confront a five-month-old opposition uprising in other parts of the country.

The protesters have been demanding an end to President Ali Abdullah Saleh's 33-year autocratic rule.