Two of five men suspected of raping a woman at a Brooklyn playground turned themselves in on Sunday evening, while two others had been apprehended and one was still at large.
The four in custody ranged in age from 14 to 17 and charges were pending, according to a police statement.
Police said on Saturday that the five men took turns raping the 18-year-old woman at the playground operated by the New York City Parks Department in the Brownsville section of Brooklyn just after 9 pm on Thursday. One man pointed a gun at the father and told him to leave, police said.
After the father left, the men each assaulted the woman, police said.
In a statement on Sunday, police said the father approached a patrol car on the street to report the assaults. Officers went to the scene immediately, but the men had fled, said the statement from Stephen Davis, deputy commissioner for public information.
"There was no delay in the police response," Davis said. "There were no 911 calls associated with the attack, contrary to media reports."
The woman was taken by ambulance to a hospital, treated and released, police said.
Police released surveillance video taken in a nearby bodega that they said showed the five suspects before the attack. The video depicts a group of black men in jackets and sweatshirts talking and laughing inside the store.
A police spokesman confirmed in an e-mail that two of the suspects turned themselves in on Sunday. A statement issued by the department said two others had been apprehended and the fifth suspect was still at large.
New York Mayor Bill de Blasio on Sunday denounced the rape, pledging police would work to swiftly apprehend the suspects.
"We will take every step possible to find and swiftly prosecute the assailants of this vicious crime," de Blasio said in a statement.
"Every New Yorker in every neighbourhood deserves to feel safe and protected, and we will not stop until the perpetrators of this disturbing attack are held accountable for their actions."
De Blasio and his police commissioner, Bill Bratton, have faced criticism over the perception that major crime is rising in America's most populous city.
Major crimes reported dropped 1.7 per cent last year and by 5.8 per cent since de Blasio took office two years ago. But some categories have increased, according to a report issued earlier this month. Rapes were up 6.3 per cent last year.