Congress Parliamentary Party leader Sonia Gandhi on Thursday urged Prime Minister Narendra Modi to discuss the Manipur situation in the House, said Adhir Ranjan Chowdhury, the party's leader in the Lok Sabha.

Gandhi made the demand during her brief conversation with the prime minister in the Lok Sabha on the first day of the Monsoon session Just before the House met for the day, Modi took a round to greet various leaders. It is customary for leaders to greet each other on the first day of the Parliament session.

As Modi reached the bench of opposition leaders, he had a brief conversation with Gandhi.

Chowdhury said during the conversation, Gandhi urged the prime minister to hold a discussion on the violence in the northeastern state.

In his customary interaction with the media in the Parliament complex ahead of the session on Thursday, the prime minister said the incident of women being paraded naked in Manipur has shamed 140 crore Indians and asserted that the law will act with its full might and no guilty will be spared.

Follow Manipur violence LIVE Updates here

"Today, when I am standing by this temple of democracy my heart is full of pain and anger," he told reporters at the Parliament complex before the start of the Monsoon session amid criticism by opposition parties for not speaking on the ethnic violence in the BJP-ruled northeast state.

"I want to assure the people of the country that no guilty will be spared. The law will act with its full might and firmness... What has happened to these daughters of Manipur can never be forgiven," he said.

The Manipur Police on Thursday arrested one of the main accused who was seen in a May 4 video of two tribal women being paraded naked and molested by a mob at a village in Senapati district, officials said.

Tension mounted in the hills of Manipur after a May 4 video surfaced on Wednesday showing two women from one of the warring communities being paraded naked by a few men from the other side.

The video was doing the rounds on the eve of a planned protest march announced by the Indigenous Tribal Leaders' Forum (ITLF) on Thursday to highlight their plight.

Manipur has witnessed ethnic violence since May 3.