Seven former Muslim rebels have been killed in the southern Philippines, military and police authorities, in an attack claimed by the Islamic State of Iraq and Syria (ISIS) group.

They said the dead were all members of the Moro Islamic Liberation Front (MILF), formerly the country’s largest guerrilla group but which began decommissioning weapons last month under the terms of a 2014 peace treaty.

A pro-ISIS armed group called Dawlah Islamiyah attacked an MILF camp near the town of Shariff Saydona on Friday, sparking fighting lasting several hours, said Lieutenant-Colonel Ernesto Gener, commander of a local army battalion.