Firefighters enter the prison Wednesday in Comayagua, Honduras. The deadly fire broke out in the facility north of the capital.
A short circuit or mattress fire may have sparked the blaze, an official says
At least 272 were killed in the prison fire in Comayagua, Honduras
The cause is under investigation, a fire official says
Tegucigalpa, Honduras (CNN)-- At least 272 inmates were dead and the fate of 105 others was unknown Wednesday as families clamored to learn whether their loved ones perished in a prison fire in central Honduras.
"Everyone ran for their lives," said one survivor, who spoke briefly to local television cameras.
The fire happened overnight in a minimum security prison in Comayagua, Honduras.
The young survivor, Alex Turcio, said he did not know how the fire started but that he and the other prisoners were asleep when they awoke to the screams of fellow inmates.
The prisoners forced themselves out of the prison any way they could, he said.
The blaze was controlled, but the exact number of fatalities remained unknown, said Jose Turcios, spokesman for the Comayagua fire department.
Some 35 prisoners were transported to a local hospital, he said, and some were then taken to a hospital in the capital.
Before dawn Wednesday, families of the prisoners were already gathering in front of the prison gates and authorities' offices, demanding to know if their loved ones were among the survivors.
Hundreds of family members pressed against the gates as an official read aloud the names of the survivors.
When they were done reading the names, some 105 inmates remained unaccounted for. It was possible that they had also been killed or that they had survived but escaped from the prison.
At one point, families of the victims clashed with security forces and forced themselves onto the premises to reclaim their loved ones' bodies.
But officials restored calm, saying that some of the bodies would require DNA analysis for proper identification.
"I understand the worry and demands of the people, but we have to abide by the law," said Pompeyo Bonilla, the country's minister of security. "We have the best intention to give answers to the families as soon as possible."
Five of the prison's units -- more than half of the facility -- were affected by the fire, Turcios said. The prison holds 851 inmates.
The cause of the blaze is under investigation, he said.
The country's prison commissioner said authorities are looking into whether a short circuit sparked the fire or if possibly a prisoner set a mattress on fire.
The blaze broke out at 11 p.m. Tuesday (12 a.m. Wednesday ET).
It was the third fatal prison fire in recent years. In 2003, 61 prisoners were killed in a fire at a prison in La Ceiba. In 2004, the death toll was 107 from a fire in a San Pedro Sula prison.
The U.S. State Department published a report last April painting a damning portrait of conditions in Honduras' 24 prisons.
Prisoners "suffered from severe overcrowding, malnutrition, and lack of adequate sanitation," it cited human rights groups as saying.
"Authorities did not provide adequate food or other basic necessities. The ready access of prisoners to weapons and other contraband, impunity for inmate attacks against nonviolent prisoners, inmate escapes, and threats by inmates and their associates outside prisons against prison officials and their families contributed to an unstable and dangerous penitentiary system environment," the department said in its 2010 Country Reports on Human Rights Practices.
Human rights groups also alleged that prison officials used excessive force against prisoners, the State Department said.
As of December 2010, the total prison population in the country was just under 12,000, about 400 of whom were women, the report said.
The security minister, Bonilla, told CNN that overcrowding in the country's prisons are the result of an increase in transnational organized crime.
Honduras, and the world, will have to decide how to respond to the security crisis in the poor nation, he said.
Danilo Orellana, the director of prisons in Honduras, added that the prisons in general were in crisis.
"The situation is grave and we have said on many occasions that the prisons in the country are failing and that investments are necessary from the state," he said.
CNN's Mariano Castillo, Laura Smith-Spark and Rafael Romo contributed to this report.