In his first reaction to incidents of violence in Delhi, Prime Minister Narendra Modi on Wednesday appealed for peace and brotherhood, and said he has held an extensive review of the prevailing situation in various parts of the national capital.

He also said it was important that calm and normalcy was restored at the earliest.

"Had an extensive review on the situation prevailing in various parts of Delhi. Police and other agencies are working on the ground to ensure peace and normalcy," Modi tweeted.

"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," he added.

At least 20 people have been killed in communal violence in north east Delhi for the last few days.