Islamist militias held their ground Thursday in the face of an assault by an ex-general backed by army units aimed at retaking Libya’s second city of Benghazi, military sources said.

Medics said at least 17 people were killed in 24 hours of fighting since Khalifa Haftar’s forces early on Wednesday launched what he called an operation to “liberate” the city.

Tanks spearheaded attacks on an Islamist militia, the “February 17 Martyrs Brigade,” while warplanes carried out raids on its headquarters in a western suburb of the Mediterranean city. […]