Garment factory worker Pradeep Kumar, 19, was arrested in the eastern state of Bihar, about 1,000km from New Delhi, and was being brought to the capital, police said.
Questioning of the first man arrested in the case, Manoj Kumar, led them to the second suspect. Manoj Kumar, 24, was arrested on Saturday in Bihar and flown back to New Delhi. Kumar is a common last name in India and the two men are not related.
They are accused of abducting, raping, and attempting to murder the little girl, who went missing on Apr 15 and was found two days later by neighbours who heard her crying in a locked room in the same New Delhi building where she lives with her family.
The child was alone when she was found, mutilated, having been left for dead by her attackers, police said.
She was critical when she was transferred from a local hospital to the largest government-run hospital in the country.
DK Sharma, medical superintendent of the hospital in New Delhi where the girl was being treated, said she was responding well and her condition had stabilised.
“She is much better today and her wounds are healing well,” Sharma said.
The attack came four months after the fatal gang rape of a woman on a New Delhi bus sparked outrage across India about the treatment of women in the country.
For the third consecutive day, protests erupted in at least three places in New Delhi.
Scores of supporters of the main opposition Bharatiya Janata Party (BJP) dodged a huge police cordon and managed to reach the gates of parliament where they shouted slogans against the Delhi police’s tardy handling of the case.
The family of the victim alleged the officers offered them a 2,000 rupee (€28) bribe to hush up the case — delaying the search for the girl by several hours.
Police have been under the spotlight for their failure to properly investigate rape allegations..
About 100 BJP supporters were detained. Police said they would be held at a nearby police station and released in a few hours.
Separately, about 100 women protested at another area near the parliament building. Most of the protests were directed against the Delhi police officers who failed to act after the girl’s parents told them she was missing.
The protesters have demanded that the Delhi police chief be removed from office and that police accused of failing to act on the parents’ complaint be dismissed.
“The police must be held accountable for their shocking levels of apathy. They urgently need to review police processes to ensure that all cases of rape and sexual violence — not just those highlighted by the media — are fully and promptly investigated,” said G Ananthapadmanabhan, who heads the India chapter of the human rights group Amnesty International.
“Those who fail to do their job must be held accountable,” he said.
Neeraj Kumar, the Delhi police commissioner, admitted that police had erred in handling the case. “There have been shortfalls, so the station house officer and his deputy have been suspended,” Kumar told reporters.
However, he said that instructions given to police officers since the December gang rape case to report all complaints of rape and molestation had led to a “phenomenal rise” in the number of such cases registered in the city.
He said the number of rape and molestation cases that police were able to solve have also gone up drastically.
Despite the police chief’s claims of tighter enforcement, sexual crimes against women and children are reported every day in Indian newspapers, and women often complain about feeling insecure when they leave their homes.
Manmohan Singh, the prime minister, called for changes in attitudes toward women in India.
“The gruesome assault on the little girl a few days back reminds us once again of the need to work collectively to root out this sort of depravity from our society,” Singh said at a meeting with civil servants.