Libyan officials say Khalifa Hifter's self-styled Libyan National Army has intensified its airstrikes over the past two days on rival militias in and around the capital, Tripoli.

The officials say Monday that airstrikes have targeted the Nawasi Brigade, one of several militias allied with a weak U.N.-supported government, in the Abu Salim district, about 7 kilometers (4 miles) from Tripoli's center.

They say airstrikes and shelling also hit the towns of Khallet al-Forjan, Ain Zara and al-Twaisha, south of Tripoli.

The officials requested anonymity because they weren't authorized to brief media.

Hifter, whose forces control much of eastern Libya, launched an offensive to retake the capital on April 4. The U.N. says the fighting has killed more than 270 people, including civilians, and displaced more than 41,000.