The clash between the Greek People's Liberation Army (ELAS), a major communist-led resistance group, and the National and Social Liberation movement marked a significant event in the complex tapestry of Greek resistance during World War II. ELAS was the armed wing of the Greek Communist Party and was active in challenging both the Axis occupiers and rival resistance factions. In 1944, as Greece continued to suffer under Axis occupation, tensions among various resistance groups became palpable. Disputes over ideology, strategies, and territorial control often led to violent confrontations.

On April 17, ELAS forces launched a concerted assault on the National and Social Liberation group, which was smaller and less organized. The onslaught not only resulted in the surrender of the National and Social Liberation members but also signified the assertive military posture of ELAS within the Greek resistance landscape. Dimitrios Psarros, the leader of the National and Social Liberation, was captured during this encounter and subsequently murdered, a fate that underscored the ruthlessness often exhibited in conflicts between competing resistance factions.

This event not only demonstrates the challenges faced internally by the resistance but also highlights how strategic objectives sometimes led to tragic results among those opposing foreign occupation. The killing of Dimitrios Psarros surfaced issues of loyalty and control among various resistance factions, questioning who would lead the post-occupation struggle in a divided nation.