India's hard-line Hindu nationalists watched anti-government protests centered in Muslim communities for months in anger that finally boiled over in the worst communal rioting in New Delhi in decades, leaving 38 people dead and the Indian capital shell-shocked.

At least seven people, including a police officer, were killed and dozens were injured in clashes between hundreds of supporters and opponents of a new citizenship law in India that provides fast-track naturalization for some foreign-born religious minorities but not Muslims, police said Tuesday.