American warplanes struck multiple targets in Libya overnight, hitting what was apparently an Islamic State training camp and a senior extremist leader, a U.S. official said Friday.

This official did not further identify the leader or the area in Libya where the airstrikes were conducted.

The official spoke on condition of anonymity to discuss an operation that has not been publicly announced.

President Barack Obama last week directed his national security team to bolster counterterrorism efforts in Libya while also pursuing diplomatic possibilities for solving its political crisis and forming a government of national unity. While the Islamic State has emerged in other places, including Afghanistan, Libya is seen as its key focus outside of Syria and Iraq.

The U.S. military has been closely monitoring Islamic State movements in Libya, and small teams of U.S. military personnel have moved in and out of the country over a period of months. British, French and Italian special forces also have been in Libya helping with aerial surveillance, mapping and intelligence gathering in several cities, including Benghazi in the east and Zintan in the west, according to two Libyan military officials who are coordinating with them. The Libyan officials spoke on condition of anonymity recently with The Associated Press on this matter because they were not authorized to speak to the press.

U.S. officials predicted early this month that it would be weeks or longer before U.S. special forces would be sent, citing the need for more consultations with European allies. Additional intelligence would help refine targets for any sort of military strikes, but surveillance drones are in high demand elsewhere, including in Syria, Iraq and Afghanistan.

Adding to the concern in Washington and Europe is evidence that the number of Islamic State fighters in Libya is increasing - now believed to be up from about 2,000 to 5,000 - even as the group's numbers in Syria and Iraq are shrinking under more unrelenting U.S. and coalition airstrikes.