NEW DELHI: A Delhi Police Head Constable was killed in Chand Bagh and a Deputy Commissioner (DCP) was injured in Gokulpuri during the violence. In disturbing videos of the clashes, which spread to Chand Bagh, Bhajanpura, Maujpur and Jaffrabad, among other areas, vehicles, shops and buildings were also set ablaze. A petrol pump was set on fire in Bhajanpura as petrol bombs were thrown by anti-CAA protesters.

In another video a man in a red shirt can be seen running towards an unarmed Delhi Police officer in Jaffrabad waving what appears to be a gun; in chilling scenes he approaches the cop and confronts him before turning and firing into the air. Other videos show people from both groups breaking off chunks from the concrete divider along the road to throw at each other. In at least one of these videos shouts of "Jai Shri Ram" can be heard.

Delhi Police resorted to firing tear gas shells in an effort to control the situation. Once the violence escalated, paramilitary forces were called in to restore peace. Delhi Metro has closed the Jaffrabad, Maujpur-Babarpur, Gokulpuri, Johri Enclave and Shiv Vihar stations. Large gatherings have been banned under Section 144.

Delhi Chief Minister Arvind Kejriwal called the violence "very distressing" and urged Union Home Minister Amit Shah - under whose control Delhi Police rolls up - to "restore law and order and ensure peace and harmony is maintained". Political analyst Yogendra Yadav also took to Twitter to raise alarm over the clashes.

Delhi Lieutenant Governor Anil Baijal said he had "instructed Delhi Police to ensure law and order is maintained". "The situation is being closely monitored. I urge everyone to exercise restraint for maintenance of peace and harmony," he said.

Donald Trump is due in Delhi at around 7.30 pm.

Sunday's violence broke out after local BJP leader Kapil Mishra, who has a history of making communal and incendiary comments, held a pro-CAA rally in Maujpur. He gave an "ultimatum" to Delhi police.

Mobile internet in Aligarh was suspended at 6 pm on Sunday and has yet to be restored. Eight people were injured in the violence - five protesters and three police officers. One of the injured protesters had a gunshot wound; the police have denied opening fire.

Massive protests have swept the country against the citizenship law, which makes religion test for citizenship for the first time in India. While government says it will grant citizenship to minorities from three Muslim-majority neighbouring countries, critics have called the law "anti-Muslim".