Athens: The protests and riots in Athens threaten to undermine tourism, one of Greece's few growth industries and the country's best hope of easing the pain of its unprecedented austerity programme.

"People will think twice about going to Greece," said Ian Gamse, a director at London-based Otus & Company, which advises Marriott International Incorporated and Hilton Worldwide. "People who have booked are going to start calling their tour operators. If Greece can't get the situation under control, it is going to be a big problem."

The demonstrations, which left three people dead and four buildings burned on Wednesday, come as the spring tourist season is getting under way. Tourism accounts for about 16 per cent of Greece's gross domestic product and about one in five jobs, according to estimates by the London-based World Travel and Tourism Council.

Greece's GDP will decline 4 per cent this year and 2.6 per cent next year, according to the Finance Ministry. European Union Economic and Monetary Affairs Commissioner Olli Rehn said on Wednesday that the austerity measures Greece agreed to for its May 2 bailout package will deepen the contraction by 1 percentage point this year and by 2 percentage points next year.

Prime Minister George Papandreou accepted the measures in return for 110 billion euros (Dh521.2 billion) in funding from the European Union and the International Monetary Fund. Union groups have called the austerity plan "savage".

Three people died in a fire in Athens set by breakaway self-styled anarchists on Wednesday during a general strike, the third this year, called against a second set of wage cuts and tax increases.