Libyan officials say forces loyal to military commander Khalifa Hifter are pursuing Islamic State militants in the country's south, killing more than a dozen militants over the past three days.

The officials said Sunday that the self-styled Libyan National Army began its attack on a militant hideout in the mountainous area of Haruj earlier this week. The officials spoke on condition of anonymity because they were not authorized to brief the media.

The LNA media center said Friday that the IS militants were responsible for recent attacks in southern areas.

IS acknowledged the ongoing LNA attack and claimed to have killed and wounded dozens of LNA troops.

Hifter's forces launched a military offensive in early April aimed at taking the capital, Tripoli, from a United Nations-aligned but weak administration.