ISTANBUL (AFP) - Around 1,000 protesters flooded an Istanbul metro station on Tuesday after a young homeless man was reportedly beaten by a security guard when he tried to board without paying.

The demonstration flared into a broader protest against the government, which has been battling a damaging political crisis sparked by a corruption probe.

In the capital Ankara, riot police confronted hundreds of demonstrators who staged a similar protest at a metro station, leaving one person injured, local media said.

"The people's rage will burn down the government," the demonstrators chanted after jumping the turnstiles in the metro at Istanbul's main Taksim Square.

"They are thieves," they shouted, referring to the graft scandal that has engulfed close allies of Prime Minister Recep Tayyip Erdogan.

Homeless man Aykut Kelek, 20, was hit in the head on Monday with a metal detector by a security guard who tried to stop him boarding the metro, media reports said.

He was taken to hospital reportedly suffering a brain haemorrhage but was discharged on Tuesday, the media said, while the security guard was detained.

Mr Erdogan - who faced a wave of anti-government demonstrations in June - is battling fresh protests in the wake of the corruption probe that has seen three of his ministers resign.

"The corruption has become brutal. Those people (the government) have stolen billions of dollars but still want to take our rights to have free transportation, even causing injuries," Mr Sevda, a 24-year old student, told AFP.

"I am angry, furious and sad. We feel terrible and the future is grim. It's a bad situation," said Ms Ada Kose, a 40-year old psychologist.

"Nobody is talking about social justice and the corruption will be covered up once again, we've seen it in the past," she said.

The fresh turmoil has erupted just three months before local elections in Turkey, seen as a key test for the country's once-unassailable strongman.