Greece is being hit by a fresh wave of strikes as trade unions oppose government reforms aimed at preparing Greece to join the European single currency.

A strike by customs officers over pension reform has severely disrupted cross-border traffic with Macedonia and Bulgaria.

At the Promachonas border crossing with Bulgaria the queue of cars and lorries was reported to extend for at least three kilometres.

Railway workers and doctors at state-run hospitals have also gone on strike and are expected to be joined later in the week by bus drivers, tax officials and school teachers.