MercoPress. South Atlantic News Agency

Bomb explodes outside bank in Chilean capital.

The group calling itself “Julio Guerra, Southern Operation” took responsibility for the blast in a phone call to Santiago's Bio Bio radio station.

The pre-dawn explosion caused considerable structural damage to a Banco del Estado office in the La Cisterna municipality, some 10 kilometers (6 miles) from downtown Santiago.

The caller said the attack had been staged in retaliation for delays in passing a bill on behalf of people imprisoned for crimes sanctioned in anti-terrorist legislation.

The explosion shattered windows within a 50-meter radius, including the large ones in another bank building across the street, officials said.

Large chunks of concrete broke off the second story of the Banco del Estado building and three ATMs were destroyed, military police Chief Lt. Col. Esteban Marcusovic said. "The explosion of this bomb is particularly serious, because it demonstrates greater destructive power and shows that this group is bigger and better organized," Deputy Interior Secretary Jorge Correa Sutil said.

Julio Guerra Olivares was one of 12 members of the Manuel Rodriguez Patriotic Front (FPMR), a guerrilla group that waged an armed resistance against the dictatorship of Augusto Pinochet. State security agents killed him in June 1987.

The attack comes two days after a McDonald's restaurant was torched during a protest by college students in the capital's Ñuñoa neighborhood.

A group of hooded individuals hurled bombs at the fast-food restaurant during the demonstration calling for the release of some 30 prisoners behind bars for more than 10 years on terrorism charges.

The inmates have been on a hunger strike since April 12.

On Wednesday, two small bombs went off at a condominium near a private university whose students were also on strike.

Minor attacks were launched last week to protest the Asia-Pacific Economic Cooperation forum in the southern city of Pucon.