CHICAGO (Reuters) - Hundreds of supporters gathered in Chicago on Thursday to celebrate a Puerto Rican activist who was freed from prison after serving over three decades behind bars for his involvement with a nationalist group that carried out more than 100 bombings in the 1970s and 1980s.

A woman passes a street mural of Oscar Lopez Rivera after his release from house arrest in Puerto Rico, ahead of his return to Chicago, Illinois, U.S. May 18, 2017. REUTERS/Timothy McLaughlin

Oscar Lopez Rivera, 74, was convicted in 1981 of numerous charges, along with other members of the Armed Forces of National Liberation (FALN), who sought to secure Puerto Rican independence from the United States.

Rivera’s 70-year sentence was commuted by former President Barack Obama in January, bringing renewed interest to his complicated legacy. Rivera has been hailed as a pillar of community organizing in Chicago and a leading voice of Puerto Rican nationalism and anti-colonialism, but denounced as a hardened criminal by critics.

His release comes at a time of tremendous turmoil for Puerto Rico - the U.S. commonwealth, home to 3.5 million people, filed for bankruptcy earlier this month.

“My mission, my mission in this world until I die, is to fight for the decolonization of Puerto Rico,” Rivera, who was born in Puerto Rico but moved to Chicago a child, said on Thursday in a speech to his Chicago backers.

In 1981, Rivera was sentenced to 55 years in prison for charges including seditious conspiracy. An additional 15 years were added to his sentence in 1988 after law enforcement foiled a plot to break him out of prison.

Rivera rejected clemency from former President Bill Clinton in 1999 because it was not extended to another imprisoned FALN member.

After his sentence was commuted by Obama, Rivera spent the final months of his incarceration in Puerto Rico. He was previously held in Indiana. He was freed on Wednesday.

On Thursday, motorcycles led hundreds of people, many waving Puerto Rican flags, through Chicago’s Humboldt Park neighborhood. Cheers of “Oscar’s free!” went up from the crowd as an honorary street sign was unveiled for Rivera.

The accolades for Rivera, who will also be honored at the National Puerto Rican Day Parade in New York next month, have upset family members of those who were killed by bombings carried out by FALN.

“What has happened since the announcement I find absolutely revolting,” said Diana Berger Ettenson, whose husband was killed by a bomb at the Fraunces Tavern in New York City in 1975.

“What were the aldermen thinking? The man is a convicted terrorist.”

No one was charged in connection with the tavern bombing.

Rivera’s release, which has been championed by some politicians and celebrities, such as Hamilton playwright Lin-Manuel Miranda, comes as Puerto Rico enters into the largest public finance restructuring case in history.

The economy has been racked by a 45 percent poverty rate, 11 percent unemployment rate and increasing emigration to the United States.

The U.S. commonwealth also suffers from a near-insolvent public health system, having spent the last 10 years in recession with debt piling up to pay for basic services.

In Chicago on Thursday, Rivera urged the Puerto Rican diaspora to lend greater support to the country.

“We need every one of you, everyone of you, to make Puerto Rico the nation that it has the potential of being,” Rivera said.