ATHENS - Strikes hit Greece on Thursday in response to a call for a national protest against draft austerity measures just as government plans to fight a debt crisis reeled from another credit downgrade.

As the Greek finance minister dashed between European capitals to reassure investors and ministers in the EU and eurozone that the government means business, thousands of school teachers, state hospital doctors, dock workers and journalists went on strike. The national day of protest is being organised by Communist-led trade unions, but two big unions led by allies of the governing socialist party have not joined in.

The protests are a new dilemma for a Socialist government struggling to restore the country's credibility on financial markets and with the European Union, where there are now fears for the solvency of other indebted eurozone members and possibly for the cohesion of the eurozone.

Finance Minister George Papaconstantinou, on a crucial tour of leading European capitals to rally support for Greece from governments, was meeting British counterpart Alistair Darling in London before going on to Frankfurt.

Prime Minister George Papandreou, under acute pressure from financial markets, had outlined on Monday a crisis strategy to curb public sector hiring, reduce civil servant benefits and overhaul the tax administration.

As the strikes, expected to spread to about 60 towns across the country, got under way, Papandreou said: 'We take seriously each international assessment that concerns and influences our country, but we have our strategy and we're going to stick to it.' But his proposals have failed to reassure nervous financial markets, while prompting warnings of fierce resistance from the country's powerful unions.