A Libyan media official says pro-government forces fighting to dislodge the Islamic State group from its key bastion of Sirte have found bodies of militants, handcuffed and shot in the head, inside army barracks in the city

Ahmed Hadiya told The Associated Press on Friday that at least six bodies were found inside the al-Saadi barracks after the facility was overrun by the forces allied to the U.N.-brokered government.

He says he believes the bodies are of IS "militants who wanted to flee."

He added that the offensive to capture the Mediterranean city is nearing its "final stage" and that IS fighters have hunkered down inside a sprawling convention center for the final showdown.

IS has exploited Libya's turmoil to gain a foothold in the North African country.