Athens  - Flights to and from Greece were to be grounded for several hours and vessels were to remain anchored Thursday during a nationwide 24-hour strike to protest against the government's economic polices.

Under the slogan "employees should not pay for the crisis," the walkout was the second nationwide protest against the conservative government since riots broke out in December, triggered by the country's bleak economy and police shooting of a teenager.

Air traffic controllers were to walk off the job for four hours from 1200 until 1600 (0900 GMT until 1300 GMT), forcing the cancellation of dozens of international and domestic flights.

The strike has been called by the country's private sector federation GSEE and public sector union ADEDY, which together represent more than half of the country's workforce of 5 million.

Newly privatised Olympic Airlines said it cancelled a total of 140 domestic and international flights, and rescheduled 11 flights to and from London, Frankfurt, Milan, Istanbul, Alexandria and Bucharest.

The private airline Aegean said it cancelled 24 flights and rescheduled another 30.

The air traffic controllers are demanding the hiring of extra staff and an improvement in their health care benefits.

The strike was also affecting all state-run schools as teachers stayed away, and all state services, including banks, ministries, tax offices, municipal buildings and state-owned power utilities as they shut their client services departments for the day.

Hospitals were fuctioning with emergency staff only, and a 24-hour news blackout was due to be imposed as print and broadcast journalists refused to show up for work.

All ferry services to and from the Greek islands were suspended as vessels remain anchored at harbours across the country while train, bus, tram and trolley services are also expected to stop operations for several hours.

Greece's unions are protesting against the government's recent pension and labour reforms, which raise the retirement age and cut back benefits as well as privatisations and tax-raising measures.

The unpopular reforms have ignited an almost daily spate of bomb and arson attacks on government buildings and businesses.

The government recently announced a public sector wage freeze and one-off taxes to those earning over 60,000 euros a year in an effort to fill badly needed coffers.

The strike follows weeks of riots across Greece in December by youths whose economic future is bleak in a country with a high unemployment rate and low wages.

Unemployment is over 7 per cent, and nearly 20 per cent of Greeks live below the poverty line, earning less than 600 euros (775 dollars) a month. Labour unions said approximately 4,000 people lost their jobs in March. (dpa)