LONDON (Reuters) - Hundreds of noisy protesters greeted Indian Prime Minister Narendra Modi when he arrived in London on Wednesday, demonstrating over a rising tide of sexual violence at home, including two particularly brutal rapes.

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Holding placards reading “Modi go home” and “we stand against Modi’s agenda of hate and greed,” they gathered outside Downing Street and parliament as Modi arrived for talks with Prime Minister Theresa May.

Modi later responded at an event in front of thousands of Indian, saying the rape cases were “a matter of great concern”, had brought “a shame” on the country and called for the perpetrators to be outed.

Sexual violence against women is a highly charged political issue in India, where protests regularly erupt about entrenched violence against women and the failure to protect them.

“The Indian government are doing nothing, and you feel sorry for the families because of the total injustice of it all,” said Navindra Singh, an Indian-born lawyer who lives in Britain.

“He has been in power for four years now and there has been no policy change to help protect women and children.”

Protests have erupted across India after the latest rape cases were reported. Police officers and a politician are under investigation in two of the unrelated cases.

In a crime that shocked India, an eight-year-old Muslim girl in the northern state of Jammu and Kashmir was kidnapped, drugged and held for several days while she was raped repeatedly and then murdered.

In the other case, a state lawmaker from Modi’s Bharatiya Janata Party stands accused of raping a teenager. No action was taken against the politician until the girl threatened to set herself on fire earlier this month. Her father died soon afterwards from injuries he suffered in police custody.

Modi’s comments on Wednesday followed remarks last week, which came after a week of silence on the issue and promised justice regardless of whoever the guilty were.

Nearly 40 percent of India’s rape victims are children, and the 40,000 reported rapes in 2016 marked a 60 percent increase over the level in 2012. But women’s rights groups say the figures are still gross underestimates.

In London, a spokeswoman for a group of UK-based Indian students and alumni - who did not want her name to be used - said the group had come under fire after it sent a letter to Modi last week demanding action over the rape cases. The letter was signed by Indian and Asian student groups from more than 20 British universities.

She told Reuters many of the university groups had received calls from “UK-based individuals” pressuring them to remove their signatures from the letter, and that members of the group had not received tickets for Wednesday’s event with Modi, although the organizers had told they would.

“The question you have to ask is are our voices being silenced,” she said.

Modi, a Hindu nationalist, is a divisive figure in India and his second trip to Britain as prime minister represents a remarkable turnaround for a man who was once banned from the UK over his alleged role, as chief minister of Gujarat, in riots that killed about 1,000 people in 2002.

Britain ended a boycott of Modi in 2012 after he emerged from being a provincial politician to the likely leader of the world’s largest democracy. He has denied wrongdoing and was exonerated by an inquiry ordered by India’s Supreme Court.