ISIS has executed four people in the coastal Libyan city of Sirte, claiming they were spies for the rival group "Libya Dawn."
A video of the incident was published on social media on Monday. The video showed ISIS gunmen shooting a man, dressed in an orange jumpsuit, who was tied to a makeshift cross. His body was left there afterwards as a warning to others.
In the beginning of the video the victim identifies himself as an alleged spy for Libya Dawn, a group which backs the Tripoli government.
Reuters quoted anonymous Sirte residents as saying ISIS has executed a total of four people, all wearing orange jumpsuits, but received no information regarding their identity.
Fierce clashes in Sirte between Libya Dawn and ISIS resulted in the deaths of around 37 people earlier this month.
Sirte, located about 500 km east of Libya's capital Tripoli, is the birthplace of the late Libyan leader Muammar Gaddafi who was deposed in 2011.
ISIS took over Sirte in February exploiting the power vacuum in Libya as a civil war rages in the country.
Libya has been plunged into a state of violent unrest since Muammar Gaddafi was deposed in 2011. Deep political divisions and tribal rivalries led to the creation of two separate governments - the House of Representatives in Tobruk and the General National Congress in Tripoli. Each boasts its own institutions and military forces.
Renewed peace talks in Geneva between the rival governments started once again in early August, after previous peace talks failed in Morocco last June.