Greek police clashed with hooded youths hurling firebombs at them Wednesday in Athens after 50,000 workers demonstrated against the government's latest round of austerity measures.

Officers fired tear gas canisters and stun grenades back at the youths, with the booming noise and smoke filling the streets near the central square .

Workers walked off their jobs, closing schools, canceling flights and shutting down shops and services across the country. The general strike was the first large-scale walkout since a new coalition government, led by conservative Antonis Samaras of the New Democracy party, was formed in June.

The protest was the latest evidence that Greeks have wearied of repeated rounds of austerity measures imposed at the demands of the country's international lenders.

Mr. Samaras has struggled to reach agreement with his coalition partners and Greece's creditors on $15 billion in new austerity measures as Athens seeks to win release of another portion of its second international bailout in two years. Opposition leader Alexis Tsipras of the leftist party Syriza said if the coalition government cannot protect Greek workers, they are forced to protest.

“If the coalition government of Mr. Samaras cannot protect the rights of Greek society, and accepts and co-signs the barbaric measures that are leading to a Greek holocaust, then it's up to the voice of the Greek people.”

The majority of the latest spending cuts are expected from slashing wages, pensions and welfare benefits.