Greece braces for general strike

Greece is braced for further turmoil after days of violence as unions stage a general strike in protest against the government's economic policies.

The strike is expected to shut down banks and offices and severely disrupt public transport across the country.

Greece has already been shaken by several days of riots

The industrial action was planned weeks ago but follows days of riots sparked by the police shooting of a teenager.

Unions have defied an appeal from PM Costas Karamanlis to cancel a rally planned for central Athens.

"We must all have a united stand against illegal actions, to clearly condemn violence, looting and vandalism," Mr Karamanlis said.

Union demands

The streets of Athens were calmer on Tuesday night after three consecutive days and nights of riots in which shops and offices were set alight and riot police battled groups of stone- and bottle-throwing youths.

However, Greek television reported that a group of about 100 Roma attacked a police station in the impoverished suburb of Zefyri, where they set a lorry on fire and tried unsuccessfully to push it into a station.

In the port city of Patras, 215km (134 miles) west of Athens, a crowd of people, including shop-owners, are said to have turned on rioters and forced them to stop a wave of destruction, says the BBC's Malcolm Brabant in Athens.

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Entrepreneurs have been sleeping in their shops to defend them against rioters and looters.

The Athens Traders Association estimates that four days of rioting has caused 1bn euros ($1.3bn, £874m) worth of damage.

Unions called off a major demonstration in Athens but will instead hold a rally outside the Greek parliament at 1100 (0900 GMT).

Workers from the two main umbrella unions - the Greek General Confederation of Workers (GSEE) and the Civil Servants Supreme Administrative Council (ADEDY) are demanding increased social spending in light of the global financial crisis, as well as higher wages and pensions.

They represent about 2.5 million workers - roughly half of the total Greek work force, according to Associated Press news agency.

Greek airlines Olympic and Aegean said they have cancelled a number of flights, ferry links are expected to be cut and train services severely disrupted.

Public transport in a number of cities, including Athens, is expected to be hard hit by the strike.

Teachers, journalists, bank clerks and public sector workers are also due to join the action.

Several 24-hour strikes against the government's economic reform policies have brought the country to a standstill this year.

'Warning shot'

The riots were triggered by the death of 15-year-old Alexandros Grigoropoulos, shot by police in Athens on Saturday, and spread to a number of towns and cities across Greece.

Witnesses say Alexandros was killed by a direct hit from a bullet

Clashes erupted near the suburban Athens cemetery where his funeral was held on Tuesday.

Two police officers have been charged in connection with the teenager's death, but results of a post-mortem to determine the trajectory of the bullet that killed him are not yet known.

The officer who fired says it was a ricochet from a warning shot fired at a group of youths who reportedly threw stones at a police car.

However, witnesses told Greek TV he fired directly at the teenager.

The protesters' frustration has been fuelled by corruption scandals and poor economic prospects for many, our correspondent says.

The opposition Socialist party leader George Papandreou has called on Mr Karamanlis to resign and call elections.

Mr Karamanlis, whose conservative party has a parliamentary majority of just one seat, has called for unity and said rioters would not be shown any leniency.