Police still have a number of "unanswered questions" after the escape of three young women who spent roughly a decade living as captives in Cleveland, but they said Tuesday they believe they’ve captured the three suspects responsible for the kidnappings.

Cleveland officials held a news conference Tuesday, one day after Amanda Berry escaped the house and called 911, saying she had been abducted and held for 10 years, and needed help.

Police responded within minutes and two other young women, Gina DeJesus and Michelle Knight, were also found at the house, along with a six-year-old child, believed to be Berry's daughter. Knight disappeared in 2002 when she was 20, Berry in 2003 when she was 16, and DeJesus about a year after that, when she was 14.

"The nightmare is over. These three young ladies have provided us with the ultimate definition of survival and perseverance. The healing can now begin," said Stephen Anthony, special agent in charge of the FBI's Cleveland division.

DeJesus’ aunt, Sandra Ruiz, told reporters that she saw all three women after they were rescued.

"Those girls, those women are so strong," she said. "What we've done in 10 years is nothing compared to what those women have done in 10 years to survive."

Three brothers have been arrested in connection with the investigation: Ariel Castro, 52, and two of his brothers -- Pedro Castro, 54, and Onil Castro, 50. Ariel Castro owns the home at 2207 Seymour Avenue, where the girls were found.

Officials said they will be interviewing the victims and the suspects in the days ahead to try to piece together exactly what occurred over the past decade.

"We have several unanswered questions. Why were they taken? How were they taken? And how did they remain undetected in the city of Cleveland for this period of time?" Cleveland Mayor Frank G. Jackson said Tuesday.

Officials made two visits to the home

During the news conference, Martin Flask, public safety director for the City of Cleveland, said officials made two visits to the home over the years. The first was in 2000 before any of the girls had been abducted, when Castro called police to report a fight in the street. Officers didn't go into the house during the call.

Then in 2004, after Berry and Knight had disappeared, investigators from the city's child and family services department went to the home to investigate a report that Castro, a bus driver at the time, had failed to drop off a student.

"He either intentionally or inadvertently left a child on the bus when he returned to the depot," Flask said.

No one answered the door when investigators knocked, however, and officials left without interviewing Castro. Investigators later determined there was "no criminal intent" and no charges were laid against Castro, said Flask.

Officials also said no neighbours had ever filed complaints about Castro’s residence and there were no records of any municipal violations at the address. The fire department and emergency services have never been called to the address.

But one neighbour, Elsie Cintron,told The Associated Press that her daughter saw a naked woman crawling in the backyard a few years ago and called police.

“But they didn’t take it seriously,” she said.  

Another neighbour, Israel Lugo, said he heard pounding on the doors of Castro's house in November 2011. Lugo said police officers knocked on the front door, but no one answered, so they left

Police Chief Michael McGrath said he thinks Berry, DeJesus and Knight were tied up at the house and held there in captivity.

All three women and the six-year-old child appeared to be in good health and were taken to a hospital Monday night to be evaluated and reunited with relatives. Deputy Chief Ed Tomba said during the news conference the six-year-old is believed to be the daughter of Amanda Berry. The four females were released from Metro Health Medical Center on Tuesday morning.

Neighbour Juan Perez told NBC's "Today" show that he rarely saw Castro or anyone else at the house.

"I thought the home was vacant. I thought he probably had another property and he would just come and check and see if everything is OK," Perez said. "I didn't even know anybody lived there."

Other neighbours, however, said they sometimes saw Castro walking a little girl to a neighbourhood playground.

Desperate 911 call

The women's escape and rescue began with a cry for help from Berry on Monday.

A neighbour, Charles Ramsey, told WEWS-TV he heard shouting and saw Berry calling out from behind a door that would only open a crack.

"I heard screaming," he said. "I'm eating my McDonald's. I come outside. I see this girl going nuts trying to get out of a house."

Another neighbour, Anna Tejeda, was sitting on her porch when they heard someone across the street kicking a door and yelling.

She said one of her friends went over and told Berry how to kick the screen out of the bottom of the door, which allowed her to get out.

Wearing pyjamas and old sandals, the nervous young woman came over and told them she'd been kidnapped and held captive.

She used Tejeda's phone to call police, who arrived within minutes and freed the other women from the house.

On a 911 call released by police, Berry declared: "I'm Amanda Berry. I've been on the news for the last 10 years."

Tomba said investigators were taking their time with the young ladies and letting them adjust to their newfound freedom before beginning intensive interviews.

"If you'd seen them last night, you would have nothing but compassion and love in your heart for them," he said.