More than 200 people have been blinded in a month after riot police hit them with shotgun pellets amid violent protests in Chile.

Hundreds of people have been hit in the eye with rubber bullets during the protests, sparking a 'health crisis' in its own right.

Chile's top medical body said 230 people had lost their sight, of whom 50 will need a prosthetic eye.

'This means that the patient doesn't only lose their vision, but they lose their actual eye,' said Dr Patricio Meza of the Medical College of Chile.

'We are facing a real health crisis, a health emergency given that in such few days, in three weeks, we have had the highest number of cases involving serious ocular complications due to shots in the eye.'

Growing anger over police brutality last night prompted Chilean singer Mon Laferte to stage a topless protest at the Latin Grammy Awards in Las Vegas.

Fire and fury: Demonstrators clash with riot police during a protest in Santiago yesterday, the latest outbreak of violence after weeks of demonstrations

Clashes: A demonstrator runs from tear gas in Santiago yesterday where protesters were also marking a year since a highly-publicised killing

Detained: Two police officers wearing helmets restrain a man as he struggles to break his arms free in Santiago yesterday

Wounded: Police carry an anti-government protester injured during clashes in Santiago

Topless protest: Chilean singer Mon Laferte last night staged an eye-catching protest against police brutality in her country at the Latin Grammy Awards in Las Vegas

Singer Mon Laferte goes topless to protest police brutality Chilean singer Mon Laferte last night staged a topless protest against police brutality in her country. The 36-year-old dropped her coat to reveal a message saying 'In Chile, they torture and kill'. 'Chile, your pain hurts me,' the Chilean-Mexican artist said as she accepted her prize at the Latin Grammy Awards in Las Vegas, reading a poem from the Chilean poet La Chinganera. The singer scooped the award for Best Alternative Music Album. Nicaraguan singer Luis Enrique also seized the moment in scooping the Latin Grammy for best folk album, a collaboration with the C4 Trio. 'Nicaragua is still at war,' he said. 'Nicaragua continues fighting to be free.' Advertisement

Riot police have frequently fired pellet guns at protesters and often fire 'at 90 degrees, which is to say directly at police,' the doctor said.

Injured people claim the national police force - known as the Carabineros - are the ones firing.

The National Institute of Human Rights said it condemned violence by protesters but said it did not justify 'the indiscriminate use' of pellet guns.

Prosecutors have opened 1,089 criminal investigations into allegations of 'institutional violence' during the first two weeks of the conflict.

On Sunday, police director General Mario Rozas said the use of pellet guns will 'be limited.'

Interior minister Gonzalo Blumel said 'we need to be very careful about introducing changes that could result in a violent situation that is actually worse.'

The blindness epidemic is the latest crisis in Chile's weeks of protests, which were sparked by a subway fare rise but have spiralled into a wider rebellion.

Held down: Chile's national police stand around an anti-government protester injured yesterday. Chileans have accused the force of blinding them with rubber bullets

A masked demonstrator walks past a raging fire which was set during the protests in Santiago

Demonstrators take cover during a protest against Chile's government in Valparaiso yesterday

A crowd of demonstrators holding makeshift shields runs along a street in Valparaiso

The demonstrations have sparked burning, looting and daily confrontations between protesters and police.

Yesterday's protests were also timed to mark one year since a young indigenous man was shot dead by police in circumstances that are still under investigation.

Camilo Catrillanca, the grandson of an indigenous leader, was shot in the head in November 2018 in a police operation in a rural community near the town of Ercilla.

The protests are Chile's biggest since its return to democracy in 1990, leaving 20 dead - five at the hands of state forces - and more than 1,000 injured.

Chileans are enraged over inequality and low wages, and are demanding reforms to health care, education, the pension system and the constitution.

The country's embattled President Sebastian Pinera has announced several measures in a bid to appease the public mood but protesters want him to quit.

A riot policeman grabs a demonstrator during a protest against the government in Santiago

A masked demonstrator stands in front of a fire as he takes part in a protest yesterday

Today the government announced it would hold a referendum next year to replace the country's dictatorship-era constitution next year, meeting a key demand.

Lawmakers in Chile's National Congress agreed to hold the plebiscite in April 2020 after hours of negotiations between the governing coalition and opposition parties.

'This agreement is a first step, but it is a historic and fundamental first step to start building our new social pact, and in this the citizenry will have a leading role,' said the interior minister.

The referendum will ask voters whether the constitution should be replaced and if so, how a new charter should be drafted, Senate president Jaime Quintana said.

It will propose three different models for a body to devise a new constitution, made up of either fully elected representatives, political appointees or an equal mix of both.

If elections to the body are needed, they will be held in October 2020 to coincide with regional and municipal ballots.

Medical staff members gather during a protest against Chile's government in Santiago

A shirtless protester wearing a backpack stands in a litter-strewn street during clashes with police firing water cannon in Santiago yesterday