"There are 20 people dead and 189 injured," a senior doctor from the Guru Teg Bahadur Hospital told Reuters on Wednesday.
Separately, an official at the Al-Hind Hospital in New Delhi told Reuters the facility had treated more than 200 injured people since Monday, many with severe injuries.
After some of the worst violence in the capital in decades, police used tear gas, pellets and smoke grenades, but struggled to disperse stone-throwing mobs.
On Wednesday, parts of the riot-hit areas were deserted, and a Reuters witness saw paramilitary and police forces deployed in much greater numbers.
Reuters witnesses saw mobs wielding sticks, pipes and stones walking down streets in parts of northeast Delhi on Tuesday, amid incidents of arson, looting and stone-pelting. Thick clouds of black smoke billowed from a tyre market that was set ablaze, as fire trucks rushed to control the flames.
Shots could be heard in the area and many of the wounded had suffered gunshot injuries, hospital officials said.
However, there were no immediate reports of any fighting on Wednesday.
"The situation is relatively better than yesterday in the violence hit areas," Atul Garg, the director of the Delhi fire department told Reuters on Wednesday, adding the fire department had stationed more vehicles and senior officials in the area.
"There are no rioters on the streets and our vehicles have been able to reach the area," he said.
At least two mosques in northeast Delhi were set on fire in the rioting. Reuters witnesses at a local hospital spoke with both Hindus and Muslims who were injured.
On Wednesday, the United States Commission on International Religious Freedom (USCIRF) said in a tweet that it was alarmed by the violence and it urged the Indian government "to rein in mobs and protect religious minorities and others who have been targeted."
The sectarian violence, which coincided with a visit to India by US President Donald Trump, erupted between thousands demonstrating for and against the new citizenship law introduced by Prime Minister Narendra Modi's Hindu nationalist government.
India's capital has been the epicentre of unrest against the Citizenship Amendment Act, which makes it easier for non-Muslims from some neighbouring Muslim-dominated countries to gain Indian citizenship.
Critics say the law is biased against Muslims and undermines India's secular constitution. Modi's Bharatiya Janata Party has denied it has any bias against India's more than 180 million Muslims.
India's Home Minister Amit Shah, who is directly responsible for law and order in the national capital area, held multiple high-level meetings on Tuesday to assess the situation and urged politicians to avoid provocative speeches that could fan tensions.
The Home Ministry also appointed a special commissioner of the Delhi Police to help bring the situation under control.