At least 19 civilians were killed in Marawi, the Philippine city besieged by IS-linked militants

These included three women and a child who were found dead near a university

Bodies of eight executed civilians were also found in a ravine outside Marawi

Most of them had shots in the head , some with hands tied behind their backs

Local residents had identified the eight as employees of a rice mill and a medical college

Attached to one of the bodies was a sign that said "Munafik" (traitor)

The discovery confirms speculation that Maute rebels had killed civilians

The military believes the act is aimed at winning the Maute recognition from the Islamic State group in the Middle East as a Southeast Asian affiliate