The Infrastructure, Transport and Networks Ministry on Monday denied that the taxi strike had disrupted the smooth running of any regional airports around the country, except for the 'Nikos Kazantzakis' international airport in Iraklion, Crete where the entrance had been blocked by taxi drivers for a short space of time late in the afternoon.

Greek taxi drivers blocked roads and blared their horns on Monday to protest at government plans to liberalise access to taxi licences, drawing criticism from officials worried about harm to the country's vital tourist trade.

The drivers lifted the blockade after about six hours but planned to continue the strike on Tuesday. They blocked roads to Athens' airport and main harbour, holding up thousands of tourists arriving on cruise ships.

The protests slowed traffic in the heart of the capital, with a noisy convoy of hundreds of taxis honking horns to oppose plans to free up licences as part of government plans to deregulate the economy required by an EU/IMF bailout.

On the island of Crete, drivers set a cab on fire in front of the prefect's office and shouted "Thieves! Thieves!" Authorities said the protests could hurt tourism, a key pillar of the country's recession-hit economy.

About 2,000 taxis had lined up on the highway leading to the capital's airport, leaving only one lane open and causing an 8 km (5 mile) traffic jam, a police official said.

The blockage at Athens' Piraeus port stopped buses drawing up alongside cruise ships to pick up passengers, but tourists could still walk to ground transportation.

Fifteen international and domestic flights had an average 20-minute delay in the morning as a result of the traffic jam, an airport spokeswoman said.