The girl was presented before the media Wednesday to describe what she called her forced role in the deadly attack. Her father, she said, joined Boko Haram and took his wife and daughter to a village in the forest in Bauchi state in northern Nigeria.
"My father took us to the bush, which was surrounded by gunmen," she said, according to a CNN translation. "I was asked if I wanted to go to heaven. When I answered, they said I have to go for a suicide mission and if I attempted to run they would kill me."
The girl and two others were taken by Boko Haram militants to Nigeria's second most populous city, Kano, and were dressed with explosives-laden devices.
The other girls set off hidden bombs that day, killing four people, police said.
"One of the girls said one of us should enter the market first," the girl told reporters. "She said we should separate when we entered the market."
The girl described how one attacker said the third girl would set off her bomb first, then the remaining two would detonate their explosives.
"I said no. I said I would not detonate," the girl said.
She was wounded by one of the explosions.
The teen escaped in a rickshaw that she took to a former home in Kano, the girl said. Neighbors saw her and made her go to a hospital. She left the explosive device in the cart, but the driver and hospital officials recognized the device and alerted authorities.
The girl told police she was forced into being a part of the attack.
CNN has not independently verified the girl's story. Police presented her to the media without her parents or a lawyer present. Officials wanted to make clear the attack was the work of Boko Haram.
"We want to disabuse the minds of members of the public. ... This is not a tribal war. It's a terrorism act like we have had in the past," Kano State Police Commissioner Adenerele Shinabad said.
Boko Haram has terrorized northern Nigeria regularly since 2009, attacking police, schools, churches and civilians, and bombing government buildings. Violence has increased sharply in recent months, just ahead of Nigeria's February elections.
The group has targeted mainstream Islam, saying that it does not represent the interests of Nigeria's 80 million Muslims and that it perverts Islam.
In April, Boko Haram militants drew international condemnation when they kidnapped more than 200 schoolgirls, many of whom they said they sold into slavery.
At least 5,000 people have died at Boko Haram's hands, according to a U.S. Congressional Research Service report, making it one of the world's deadliest terrorist organizations.