Angered by a prison fire in Honduras that officials say killed more than 350 trapped inmates, rights advocates on Wednesday decried dangerous and overcrowded conditions that they say have long typified the country’s neglected prison system.

Officials said at least 356 people were confirmed dead by late Wednesday, after the blaze a day earlier consumed half the prison in the town of Comayagua in central Honduras. The toll is the highest from any prison fire in modern history.

Rights advocates called for reforms of Honduran prisons, which for many years have been beset by chronic overcrowding, poor sanitation, inadequate food and ramshackle quarters. Honduran authorities have promised to earmark more funds to fix the problems but failed to do so, activists say.

“This isn’t news to the Honduran government. The tragedy that happened last night could have been avoided,” said Vicki Gass, a senior associate at the Washington Office on Latin America, or WOLA. “They’ve been told that they need to increase resources into the prison system and carry out prison reforms.”

New York-based Human Rights Watch urged an “overhaul” of Honduran prisons, saying the country’s spiraling homicide rate has sent the number of arrests soaring, leading to worse crowding.

In Comayagua, investigators sought to identify scores of bodies, many burned beyond recognition after a prisoner reportedly set fire to his mattress late Tuesday. Inmates suffocated or burned to death in their cells when rescue workers were unable to find guards with keys. Some prisoners escaped by ripping open the roof.

The prison reportedly held about 850 inmates, who grew crops in nearby fields. Television video showed emergency workers racing on foot in midnight darkness and later carrying burned survivors, some bearing broad patches of charred skin.

The head of the Honduran prison system, Danilo Orellana, told the Associated Press that survivors said the blaze started when an inmate ignited his bedding, saying, “We will all die here!”

Comayagua Gov. Paola Castro, who once worked at the prison, told reporters that an inmate telephoned her shortly before the fire, vowing to set the place ablaze and to kill everyone inside, the news service said.

Survivors were treated in hospitals in Comayagua and in the Honduran capital, Tegucigalpa, about 38 miles to the south.

Honduran President Porfirio Lobo announced he was firing top administrators from the Comayagua facility and the broader prison system while officials sought more details about what happened.

“We will do a full investigation to determine what caused this sad and unacceptable tragedy,” Lobo said in a televised statement.

Hundreds of anguished family members gathered at the prison gates to learn about the fates of the inmates, but information was mostly in short supply. The relatives clashed briefly with police, according to news reports from the scene.

The blaze was the latest in a series of deadly fires and riots in Honduran prisons in recent years. Rioting by inmates is common in Honduras and elsewhere in Latin America, where prison conditions are generally squalid and unsafe.

More than 100 inmates died in a riot and fire at a Honduran prison in San Pedro Sula in 2004, and at least 69 were killed in a disturbance a year earlier in La Ceiba. Nine people died in a riot in October last year.

“This reflects the utter crisis, deterioration and failure of the so-called penitentiary system, which isn’t really a system at all but a collection of decrepit, badly constructed, foul-smelling jails,” said Victor Meza, a former Honduran interior minister who runs a think tank called Honduran Documentation Center.

Severe crowding is attributed to a crime epidemic in Honduras and a deeply flawed justice system that sweeps up suspects, then often leaves them to languish behind bars.

The country’s two dozen prisons were built to hold up to 8,000 inmates but instead accommodate up to 13,000, owing in part to a 2003 antigang law that has swelled arrests, according to WOLA.

Honduras, which like much of Central America has become a drug-trafficking highway to the United States, suffers one of the world’s highest homicide rates. Judicial institutions, including prisons, are poorly administered and underfunded.

The State Department’s country report on human rights for 2010 described prison conditions in Honduras as “harsh,” citing reports of risks to inmates that include unsafe living conditions and even torture.

The report says: “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.”

Security Minister Pompeyo Bonilla said the growing presence of organized crime in Honduras has “logically” fed the country’s prison population.

“We have to come up with an immediate response because we can’t allow our country, Honduras, which has had three incidents of this kind, to go down that road,” he said Wednesday in a television interview.

Honduras is not alone. Prison conditions have worsened across the region as inmate populations swell, in part because of crime sweeps aimed at tackling the growing presence of international drug traffickers and homegrown street gangs.

In Mexico, where President Felipe Calderon declared war on drug cartels in 2006, thousands of drug suspects have been housed in poorly run state prisons because the federal installations lack space.

By 2010, the ranks of federal prisoners in Mexico had quadrupled in four years to more than 12,000, Public Safety Secretary Genaro Garcia Luna said at the time.

ken.ellingwood@latimes.com

Times staff writer Tracy Wilkinson in Mexico City and special correspondent Alex Renderos in San Salvador contributed to this report.