Clashes between Islamic State and rival militants in Sirte, Libya, kill 25

SIRTE, Libya, Aug. 16 (UPI) -- Street battles Friday between an affiliate of the Islamic State and rival militants in Sirte, Libya, killed at least 25 people, according to reports.

IS fighters, who captured most of Sirte earlier this year, fought a Salafist Muslim group -- as well as several armed civilians -- in a residential neighborhood of the city following the death of a local cleric and others who refused to pledge allegiance to IS, the BBC reports.

The armed civilians, who joined the fight out of anger, comprised the majority of casualties.

Last November, a recently-formed group known as Majlis Shura Shabab al-Islam declared allegiance to IS and seized the city of Derna. The following month, U.S. officials acknowledged IS had established training camps in eastern Libya.

The group, which has called itself Tripoli Province of the Islamic State, has since claimed responsibility for a number of incidents, including the execution of two Tunisian journalists and an attack at a hotel in Tripoli that killed at least 10 people in January.

In February the group released a video depicting the decapitation of 21 Coptic Christians, predominantly from Egypt, prompting Cairo to green light airstrikes against the militants. The men had reportedly been abducted in Sirte in January and February.

Libya has suffered instability following the 2011 overthrow of Muammar Gaddafi. Rebel forces turned against one another, with one side forming an internationally-recognized government in Tobruk, to the northeast, and rival factions forming the General National Congress in Tripoli, to the west. Both sides agreed to a United Nations-backed ceasefire in January, but several militant groups not aligned with either side have not agreed to the arrangement.

Last week, Abdullah al-Thinni, the prime minister of the Tobruk government, announced his resignation amid criticism of being unable to resolve the violence in Libya.