RNA - In a Twitter post on Wednesday, Modi, who had kept silent over the violence, said it was important that calm be restored to the city of more than 18 million people.
"Peace and harmony are central to our ethos. I appeal to my sisters and brothers of Delhi to maintain peace and brotherhood at all times," Modi tweeted.
At least 22 people have so far been killed and nearly 200 wounded in days of sectarian violence in India’s capital. The violence erupted between thousands demonstrating for and against a new citizenship law introduced by Modi's Hindu nationalist government.
Police and paramilitary forces patrolled the streets in far greater numbers on Wednesday. Parts of the riot-hit areas were deserted.
Witnesses saw mobs wielding sticks and pipes walking down the streets in parts of northeastern Delhi on Tuesday, amid arson attacks and looting. At least two mosques were set on fire.
On Wednesday, the United States Commission on International Religious Freedom (USCIRF) said in a tweet that it was alarmed by the violence in India, urging the government "to rein in mobs and protect religious minorities and others who have been targeted."
Modi's appeal came after a storm of criticism from opposition parties of the government's failure to contain the violence, despite the use of tear gas, pellets and smoke grenades.
Sonia Gandhi, president of the opposition Congress party, called for the resignation of Home Minister Amit Shah, who is directly responsible for law and order in the capital.
India has been engulfed by protests since early December, when the parliament passed the citizenship act, which is seen as discriminatory toward Muslims. Under the law, migrants from Bangladesh, Pakistan, and Afghanistan will be allowed to claim Indian citizenship — but not if they are Muslims.
The latest outbreak of violence coincided with a visit by US President Donald Trump, who held bilateral meetings with Modi in New Delhi earlier on Tuesday.
The Modi administration is accused of encouraging religious intolerance and seeking to transform India into a Hindu state.
Critics say the new law in India is a grave threat to its secular constitution.
Modi's ruling Bharatiya Janata Party (BJP) has denied it has any bias against India's more than 180 million Muslims.