Police in northern India arrested a Hindu nationalist governing party youth leader for making anti-Muslim comments on social media after another party official’s insulting statements about the Prophet Mohammad sparked a diplomatic row, officials said on Wednesday.

Harshit Srivastava, a member of Prime Minister Narendra Modi’s Bharatiya Janata Party’s youth wing, was arrested in Kanpur city last week when communal tensions erupted during a Muslim demonstration over anti-Islam remarks.

“We arrested the local politician for making inflammatory remarks against Muslims,” said Prashant Kumar, a senior police official, adding that at least 50 people were taken into custody following the tensions in Kanpur.

Srivastava’s lawyer was not available for a comment.

Sporadic unrest was reported in other parts of the country after the comments against the Prophet by BJP spokeswoman Nupur Sharma during a television debate.

She has been suspended from the party while another spokesman, Naveen Kumar Jindal, was expelled over comments he made about Islam on social media, the BJP has said.

Domestic outrage gained fresh momentum after leaders from Islamic nations such as Qatar, Saudi Arabia, the UAE, Oman, Indonesia, Malaysia, Pakistan, Iran and Afghanistan demanded apologies from the Indian government and summoned diplomats to protest against the anti-Islam remarks.

The influential 57-member Organisation of Islamic Cooperation (OIC) said in a statement that the insults came in the context of an increasingly intense atmosphere of hatred toward Islam in India and systematic harassment of Muslims.

India’s foreign ministry said on Monday the offensive tweets and comments did not in any way reflect the government’s views.

The controversy has become a diplomatic challenge for Modi who in recent years has cemented strong ties with energy-rich Islamic nations.

Instructions have been issued to several members of his Hindu nationalist party to be “extremely cautious” when talking about religion on public platforms.

Members of Islamic rights group in India said that it was the first time influential foreign leaders had spoken out against what they called the humiliation experienced by the minority community.

“Our voices have finally been heard, only world leaders can nudge Modi’s government and his party to change their attitude towards Muslims,” said Ali Asghar Mohammed, who runs a voluntary rights group for Muslims in Mumbai city.