Two unionists representing metro workers were injured on Monday after an apparent falling out with representatives of the union for employees of the Athens-Piraeus electric railway (ISAP).
The unionists met to discuss the new employee regulations for all employees on the metro, ISAP and tram networks.
However, it appears there was disagreement over this issue, as well as whether any further protest action should be held.
The head of the metro workers? union, Antonis Stamatopoulos, and a colleague were allegedly attacked by five people after the meeting.
Both men were taken to a local hospital but had not suffered serious injuries.