(CNN) — Seven people have been arrested and two more are sought in a string of brutal, anti-gay hate crimes against four men, New York City Police Commissioner Ray Kelly said Friday.

“Three victims were held against their will by as many as nine assailants who beat them” in a vacant apartment, and “the fourth individual was beaten and robbed elsewhere in connection to these attacks,” Kelly said in a news conference.

The string of attacks, which occurred Sunday, began when members of a street gang calling themselves the Latin King Goonies learned that an aspiring member was gay, the police commissioner said.

According to Kelly, the 17-year-old pledge was forced into an unoccupied apartment around 3:30 a.m. Sunday and questioned about his contact with a 30-year-old man. He was thrown into a wall, forced to strip naked, hit in the head with a beer can, cut with a box cutter and sodomized with the wooden handle of a plunger, the commissioner said.

His assailants let him go, but threatened to hurt him or his family if he talked, Kelly said.

The victim went to a hospital for treatment, but claimed his injuries were from an attack by unknown assailants on the street, the commissioner said.

At about 8:30 p.m on Sunday, another 17-year-old was beaten and questioned about the same 30-year-old man, robbed of jewelry and held against his will in the same vacant apartment, Kelly said.

At 9:30 p.m., the 30-year-old man was lured to the location where that 17-year-old was being held, was forced to strip naked and was tied to a chair opposite the teenager, Kelly said. The teenager was forced to hit the older male several times in the face and burn him with cigarettes, after which the suspects assaulted him with their fists and a chain and sodomized him with a small baseball bat, the commissioner said. The 30-year-old man was later dumped outside his home, he added.

Five of the suspects then went to the apartment the victim shared with his older brother and let themselves in using a key they’d taken from the man, Kelly explained. They beat the man’s brother and demanded money from him. When he refused, the assailants put a cell phone to his ear and he heard his younger brother say that he was being held against his will and to “give them the money,” the commissioner said. The older brother told the suspects where they could find the money, after which they tied him up and left the apartment, Kelly added.

The commissioner said a search of the apartment Wednesday where three of the victims said they were beaten revealed very little. He said the suspects likely returned to the scene and cleaned the rooms with bleach and repainted the walls.

The hate crimes task force took over the investigation, Kelly said, and coordinated with the Bronx Gang Division and Bronx Special Victims Squad to help identify and capture the seven suspects. Pending charges against them include: unlawful imprisonment, abduction, sodomy, assault, robbery, and menacing, all as hate crimes, the commissioner said.