Riot police clashed with demonstrators outside the Greek parliament yesterday as a general strike paralyzed the country, shutting down schools, hospitals and international flights and raising pressure on the government reeling from four days of riots.

More than 10,000 people marched through the center of the city to protest against the conservative government's economic policies.

Riot police fired tear gas when a small group of youths threw Molotov cocktails and rocks at them near the parliament in the heart of the Greek capital.

Flights to and from Athens International Airport were canceled, and public hospitals across Greece were operating with a skeleton staff. Schools and universities were closed.

The lawyer for the two policemen accused of shooting a teenager that set off the unrest said ballistics show 15-year-old Alexandros Griogropoulos was killed by a ricochet and not a direct shot. But the authorities have not made the ballistics report public.

The riots and demonstrations were set off by anger at the shooting but fed by months of widespread discontent with the conservative government of Prime Minister Costas Karamanlis, whose party holds a single seat majority in the 300-member parliament.

Lawyer Alexis Cougias said the report corroborated the policemen's account that they had fired warning shots and did not shoot directly at the boy.

One policeman has been charged with murder and the other as an accomplice. Both were to appear in court later in the day.

Karamanlis has faced growing opposition over changes to the country's pension system, privatization and the loosening of state control over higher education, which many students oppose because they fear it would undermine their degrees.

The government's support has dropped lower as groups of youths maraud through cities across the country, torching businesses, looting shops and setting up burning barricades across streets.

Storeowners have accused riot police of leaving their businesses unprotected as rioters smashed and burned their way through popular shopping districts.

Although policemen have fired volley after volley of tear gas when attacked by rock or Molotov cocktail-throwing protesters, they have held back when youths turned against buildings and cars.

Early yesterday, media reports said groups of civilians had begun taking matters into their hands, confronting looters in the western city of Patras and the central city of Larissa.

Opposition Socialist leader George Papandreou alleged that the conservatives were incapable of defending the public from rioters. But Karamanlis has so far ignored mounting calls for him to resign and call early elections.

An opinion poll for the conservative daily Kathimerini published yesterday found 68 percent Greeks, including nearly half of respondents who voted for Karamanlis' conservative party in general elections last year, believed the government mishandled the crisis. Only 18 percent of the respondents said his response had been proper.

The Public Issues survey was based on a sample of 478 people questioned on Monday and Tuesday and had a 4.5 percent margin of error.

Greece has a long history of activism. It was a student uprising that eventually brought down a seven-year military junta in 1974. Tensions persist between the security forces and a group of deeply entrenched leftist groups that often protest globalization and US foreign policy in the Middle East and elsewhere.

The groups have now mainly evolved into various youth factions that claim to fight trends ranging from globalization to police surveillance cameras. But their impact is usually limited to graffiti and late-night firebomb attacks on targets such as stores and cash machines.