What is happening in India’s Manipur?

A graphic video of two women being sexually abused in public in India’s northeastern state of Manipur has provoked outrage and condemnation.

Police have arrested at least four people accused of abduction and gang rape and are tracing at least 30 others. The crime took place as ethnic clashes between the mostly Hindu Meitei and mainly Christian Kuki-Zo communities engulfed the remote state.

Here is what you need to know about the incident:

What happened?

A clip went viral on Wednesday showing two women said to be from the Kuki-Zo group walking naked along a street, being jeered and harassed by a mob reportedly from the Meitei community.

The video emerged more than two months after it was filmed due to an internet ban in Manipur since May 3.

Violence erupted at the time between the majority Meitei and the minority Kuki-Zo over job quotas and land rights. Intermittent clashes have continued since.

The unrest was triggered by a court order that the government should consider extending special benefits enjoyed by the Kuki-Zo people to the Meitei population as well.

How did the violence start?

The violence erupted after the Kuki-Zo community protested against Meitei demands for reserved public job quotas and college admissions as a form of affirmative action and over long-held fears that they might also be allowed to acquire land in areas currently reserved for tribal groups.

At least 130 people have been killed and more than 50,000 have fled their homes since the violence began. Tens of thousands have fled to government-run camps. Homes and churches in dozens of villages have been torched.

In a detailed report to the Supreme Court in June, the civil society group Manipur Tribal Forum said many gruesome acts of violence, including rape and beheadings, had not been investigated by state authorities.

How have authorities reacted?

The main suspect in the sexual abuse case, identified as Khuirem Herodas, a Meitei, was arrested on Thursday.

He was taken into custody hours after Prime Minister Narendra Modi broke his nearly 80-day silence on the violence in Manipur by condemning the alleged sexual assault as “shameful” and promising tough action.

Also on Thursday, India’s Supreme Court said it was deeply disturbed by the viral video and asked the state and federal governments to inform the top court of the steps taken to catch the perpetrators.

If authorities do not act, “we will”, the court said.

Authorities in Manipur, led by Modi’s Hindu-nationalist Bharatiya Janata Party (BJP), said police had taken action as soon as the video surfaced on social media.

A “thorough investigation” was under way, the state’s chief minister, N Biren Singh, tweeted on Thursday.

“We will ensure strict action is taken against all the perpetrators, including considering the possibility of capital punishment,” he added.

How has the public reacted?

The video of the naked women sparked protests across India on Friday with demonstrators calling for the state’s chief minister to step down over the delay in taking action.

Women in Manipur, meanwhile, attacked the house of the main suspect.

“Local women pelted stones and burnt some parts of the house belonging to the prime accused in a village,” said Hemant Pandey, a senior police official in the state capital, Imphal.

Protests were planned in several parts of India by rights groups demanding justice and swift investigations into the latest incident to raise questions about the safety of women in India.

“What we are seeing in today’s Manipur is one of the darkest times in our history,” Binalakshmi Nepram, of the Northeast India Women Initiative for Peace, told Al Jazeera.

“What has happened to our sisters – this and so many other unreported cases of sexual assault have been happening in the state of Manipur, not just from May 3 onwards but sexual assault and rape in conflict; rape has been used as a weapon of war.”