Three people accused of being members of an anarchist cell in Chile will be formally charged Tuesday in connection with a subway station bombing that spread fear and alarm in the country earlier this month.

Prosecutors said they have "scientific proof" that the suspects conspired and carried out the attack as part of a "compact and hermetic cell" described as anarchist in nature. The government has sought to allay concerns that anarchists were unfairly profiled in the search for the culprits.

Juan Flores Riquelme, 22, is accused of being the "author" of the bombing, while Guillermo Durán Méndez, 25, and Nataly Casanova Muñoz, 26, were named by prosecutors as "accomplices to the crime of placing and manufacturing explosive devices."

As Chile has struggled to respond to a string of bombings in recent years that have mostly caused few injuries, leftist politicians and influential student leaders have hinted in public statements that the incidents could be part of an underground conspiracy by Chile's extreme right.

But evidence initially laid out by Chile's police against the three suspects appears strong.

Police reportedly found gunpowder and material used to manufacture explosives as they inspected the suspects' homes in an operation that began September 18, Chile's Independence Day. Comparative results from DNA and fingerprints recovered at the scene of the explosion are still pending.

Authorities said the suspects carried out the September 8 attack at a shopping center linked to the Escuela Militar subway station in the wealthy Las Condes district of Santiago, the capital. The most serious injuries were sustained by a cleaning lady who lost a finger when the device — a fire extinguisher filled with gunpowder and fitted with a clock — blew up just after 2pm that Monday.

The Escuela Militar station bombing was the latest in a string of at least 29 explosives-related incidents attributed this year to what authorities call a trend of "anarcho-terrorism." But some of the attacks have sometimes been sloppily linked to anarchists, stoking complaints of unfair profiling.

The bombing left a total of 14 people injured and prompted the government to invoke its "anti-terrorist" law in the case, which allows prosecutors to call anonymous witnesses against suspects and seek tougher penalties on convictions. The law is a constitutional exception with roots dating to the dictatorship of Augusto Pinochet, which ended in 1990.

Critics say the anti-terrorist law weakens fundamental rights related to the presumption of innocence under Chilean justice.

"There was a multidisciplinary team. This was a conscious effort," said Gustavo González Jure, general director of Chile's federal police force, the Carabineros. More than 200 Carabineros were involved in the operation, he added.

"This result was not the product of randomness," González said.

The three suspects caught last week will also faces charges linked to the planting and detonation of a bomb inside an empty subway car in July, authorities said. The suspects' attorney, Eduardo Camus, indicated that his clients "have denied participating in these acts."

A group calling itself the Conspiracy of the Cells of Fire, or CCF, took responsibility for both of the subway attacks in a communique that was briefly available online last Thursday. The statement was originally hosted on the website Contrainfo, an international anarchist network site, and spread from there to news outlets.

For unknown reasons, the site is no longer accessible. But the full text of the statement is recoverable in online cache form.

It reads in part: "Our faction of the Conspiracy of the Cells of Fire (CCF) decided to attack the Los Dominicos metro station on July 23. The act caused a great political and media flurry. The bureaucrats and media coordinated their discourse to say that the attack was directed at passengers who were traveling at the time, and that is why they invoked the anti-terrorist law."

"This is why on September 8, we decided to attack the Escuela Militar station — a commercial plaza for the bourgeoisie, located in Las Condes, where businessmen do what they do to accommodate themselves, and commercialize the goods that enslave the people with the stupidity of spectacle and appearance," the statement continued.

The CCF, however, said the attacks were not meant to cause injury.

"Our target was not consumers or workers, but the structures, properties and enforcers of power," they stated. "We called [authorities] more than 10 minutes before the blast, waiting for police to react by evacuating, but they ignored it, detonating the device [sic] and causing several injuries, which we lament."

Authorities have not said if the statement has been verified as legitimate, or whether its contents will be used in court against the three suspects. Chilean officials, meanwhile, said more arrests could follow.

"This represents a very important step, because it shows us that a coordinated, professional, and permanent effort is the path to clear up these events, and punish those responsible, using the full extent of the law," said President Michelle Bachelet.

"This result was not the product of randomness."

The Escuela Militar station case is being closely watched, as the last time the government sought prosecutions in high-profile bombing incidents — a drawn-out legal battle known as the "Caso Bombas" — the case largely fell apart, embarrassing officials.

"Caso Bombas" began in 2009 and concluded in late 2013, resulting in just one definitive conviction despite more than 20 arrests. A 41-year-old sociologist, Hans Niemeyer, was sentenced to five years in prison for detonating a bomb at a bank, although concrete ties to a terrorist group were never proven.

The formal charges expected Tuesday come as a separate case is revived against another man in Santiago accused of planting a bomb. Victor Montoya, now 23, spent 16 months in prison while facing charges of planting a bomb at a Carabineros checkpoint in Santiago in February 2013.

Courts eventually annulled his charges and freed Montoya, but on September 10 — a day before the anniversary of the 1973 military coup and two days after the Escuela Militar station bombing — an appeals court reversed that decision, forcing Montoya to face the exact bombing charges once more.