Clashes break out in central Athens as striking public sector workers and protesters march against austerity measures.

At least 16,000 anti-austerity protesters have converged in central Athens, chanting slogans, banging drums and blowing whistles in a display of opposition to the Greek government's latest austerity measures.

The vast majority of demonstrators were peaceful, but a few dozen protesters clashed with riot police, Al Jazeera's Jonah Hull reported from the Greek capital on Wednesday.

Masked youth threw stones, sticks, petrol bombs and other projectiles at police lines. The police responded by firing tear gas grenades, chasing the protesters and dragging them away.

The march was organized by union members and workers from the public sector, which is staging a 24-hour general strike over government plans that would see 30,000 civil servants put in a 'labor reserve' program, which effectively means they will lose their jobs within months.

Schools, government offices, museums and archaeological sites were all closed on Wednesday, while hospitals were operating with reduced staff numbers.

“One in five people are employed in the Greek public sector, so these strikes comes at an enormous cost, which Greece can't afford in the current climate,” our correspondent said.

“Ongoing strikes are becoming the norm, and if the Greek public believe the bailouts will work, then they wouldn't come out on the streets and strike. The Greek public are against more austerity and taxes.”

The labor reserve plan, accompanied by layoffs at scores of state entities, is designed to ease the state payroll struggles to balance its bulging deficit.

Evangelos Venizelos, the Greek finance minister, said on Tuesday that the government had enough cash to pay pensions, salaries and bondholders until mid-November.

Greece had previously said it needed more money by mid-October to avoid a default.

The additional austerity cuts are mandated by Greece's international creditors, the EU, IMF and European Central Bank, under an economic recovery program launched last year in return for a $149bn loan.

The crisis has sent stock markets tumbling, with European banks under extreme pressure over their possible exposure to a Greek default on government debt

The Athens stock exchange plunged to an 18-year low on Tuesday after EU officials postponed a Greek debt bailout.

The EU delayed the release of loan funds, demanding Athens make more sacrifices and warning banks may have to shoulder more losses as part of the resolution of the debt crisis.