The assault and humiliation of two women paraded naked in a Manipur village in May sparked nationwide outrage on Thursday with Prime Minister Narendra Modi saying the incident had shamed 140 crore Indians and the Supreme Court terming it “simply unacceptable”.

As the two women were catapulted to the centre stage of national attention with a 26-second video of the May 4 mob violence in Manipur's Senapati district going viral, opposition parties joined in the debate and disrupted Parliament proceedings. Police in the northeast state arrested one of the main accused who is prominently seen in the clip and alleged to be the mastermind.

Officials said several police teams had been formed immediately after the video of the incident surfaced on Wednesday and the first arrest in the case was made in Thoubal district. A case of abduction, gangrape and murder against unidentified armed persons has been registered.

The law, stressed the prime minister, will act with its full might and no guilty will be spared.

"My heart is full of pain and anger," Modi told reporters in his first remarks on the ethnic violence in the northeast state amid criticism by opposition parties for not speaking.

"What has happened to these daughters of Manipur can never be forgiven," he said ahead of the Monsoon session of Parliament.The incident has insulted the entire country and the 140 crore Indians are feeling ashamed, the prime minister said.

He also requested all chief ministers to further strengthen law and order mechanism in their states.

Manipur Chief Minister N Biren Singh said a thorough investigation is underway into the incident over two months ago and strict action, including possible capital punishment, will follow.

"My hearts go out to the two women who were subjected to a deeply disrespectful and inhumane act, as shown in the distressing video that surfaced yesterday… Let it be known, there is absolutely no place for such heinous acts in our society," he tweeted.

The anguish found echo in the Supreme Court where a bench headed by Chief Justice of India D Y Chandrachud took cognisance of the video and asked the Centre and Manipur government to take immediate action.

“We are very deeply disturbed by the videos which have emerged yesterday about the way those two women were paraded in Manipur," said the bench, also comprising Justices P S Narasimha and Manoj Misra.

"I think it is time that the government really steps in and takes action because this is simply unacceptable," the CJI said, adding, "We will give a little time to the government to act, otherwise we will take action if nothing is happening on the ground." Justice Chandrachud said using women as an instrument to perpetrate violence in an area of communal strife is "deeply disturbing" and this is "simply unacceptable".

He also termed it the "grossest" Constitutional and human rights violation. The CJI added that the court is conscious of the fact that the video is of May 4 but that makes no difference.

Proceedings in the Lok Sabha and the Rajya Sabha, meeting for the first day of the Monsoon session, were disrupted and adjourned for the day with opposition MPs creating an uproar and demanding a discussion in Parliament.

Opposition parties, including the Congress, Shiv Sena and DMK, took up the issue in a big way.

Hitting out at the government, Congress general secretary Jairam Ramesh said the prime minister had broken his silence on Manipur but it was “too little too late”.

Accusing the Centre of turning democracy into a "mobocracy", party president Mallikarjun Kharge said "humanity has died in Manipur" and asked Modi to speak about the ethnic violence-hit state in Parliament and tell the nation what happened.

Echoing him, Shiv Sena MP Priyanka Chaturvedi said, "This incident is shameful for the whole country. It is very disturbing." "We will raise the issue. We will be the voice of women who have faced violence in Manipur. Prime Minister Narendra Modi should make a statement to the people of the country through Parliament." "An insensitive and cruel leader is leading this country. Manipur is burning and Modi ji is silent," said AAP MP Sanjay Singh.

DMK president and Tamil Nadu Chief Minister M K Stalin said he was “absolutely heartbroken and appalled” by the violence unleashed on the women and demanded the Centre take action to restore peace.

“Where is our collective conscience? The hate and venom are uprooting the very soul of humanity," he said on Twitter.

The government has asked Twitter and other social media platforms to take down a video of two Manipur women paraded naked, since the matter is being probed.

Sources said the videos were inflammatory, and as the matter is under investigation, Twitter and other social media companies have been asked to remove the video.

On Wednesday night, Union Women and Child Development Minister Smriti Irani said she spoke to the Manipur chief minister who informed her that investigation is currently underway and assured that no effort will be spared to bring perpetrators to justice.

The National Commission for Women has taken suo motu cognisance of the incident.

More than 150 people have lost their lives and several injured since ethnic violence broke out in Manipur on May 3, when a 'Tribal Solidarity March' was organised in the hill districts to protest against Meitei community's demand for Scheduled Tribe (ST) status.

Meiteis account for about 53 per cent of Manipur's population and live mostly in the Imphal Valley, while tribals, which include Nagas and Kukis, constitute 40 per cent and reside mostly in the hill districts.