Islamic State militants have seized another town in Libya, the group and a military source said on Friday, expanding the territory they control in the strifetorn country.

The militant group, which controls large parts of Iraq and Syria, has exploited a security vacuum in Libya as two rival governments struggle for power, four years after the ousting of Muammar Gaddafi.

Islamic State took over the city of Sirte on Libya’s central Mediterranean coast in stages this year, occupying government buildings and last month the city’s airport. […]