Riot police used tear gas to disperse protesting truckers and prevent a highway blockade, as protests against government labor reforms entered a third week.
Police say one man was arrested during Monday's brief clashes.
Truckers have lined up their vehicles along highways, defying a government emergency order to return to work, angry at plans to liberalize restricted licensing rules.
Union protests also have brought national rail services to a standstill through Tuesday and disrupted metro rail services to Athens International Airport.
The reforms were agreed as part of deal for crisis-hit Greece to receive euro110 billion in rescue loans over three years.