Thousands of mourners paid their final tributes Saturday to Berta Caceres, the indigenous activist killed on Thursday, demanding justice for the renowned environmentalist.

The 45-year-old head of the Civic Council of Indigenous and People's Organizations (COPINH) was gunned down in her hometown of La Esperanza, 125 miles (200 kilometers) northwest of the Honduran capital Tegicigalpa, in what her family has called an assassination.

Mourners from across the country attending the funeral in La Esperanza chanted "Justice, justice!" "Berta lives!" and "The struggle continues!" as her coffin was taken to a church service before its burial.

Caceres's brother Gustavo, one of the first to find her body, told AFP that at least two masked men entered the back of the house where his sister was sleeping early on Thursday.

She got up to investigate the noise and confronted the men, who fractured her arm and leg before shooting her at least eight times at point blank range, he said.

A bullet also wounded Gustavo Castro Soto of the organization Friends of the Earth Mexico, who had been sleeping in the next room, when he came out to see what was happening. The attackers fled after he pretended to be dead.

Caceres lived in the house, which belongs to her mother, until moving out two months ago.

"Now we understand it was a way to protect her family," Gustavo Caceres said.

A mother of four who would have turned 45 Friday, Caceres rose to prominence for leading the indigenous Lenca people in a struggle against a hydroelectric dam project that would have flooded large areas of native lands and cut off water supplies to hundreds.

In 2015, she won the Goldman Environmental Prize, considered the world's top award for grassroots environmental activism.

She persevered in her activism despite numerous death threats.

Caceres was arrested in 2013 for illegal possession of firearms in what critics say was harrassment. She was acquitted in 2014.

Caceres's killing has drawn international condemnation, including from the United Nations, the United States and many environmental activists.

The activist's family has accused the authorities of trying to mask her death as a random murder, insisting that she was assassinated because of her activism against environmental destruction by large mining and hydroelectric companies.

They also accuse the government of responsibility in her murder for failing to provide protection and investigate the threats against her.

Protests erupt at memorial for slain Honduran activist
Tegucigalpa (AFP) March 5, 2016 - Mourners broke into protest Friday at a memorial service for slain Honduran indigenous activist Berta Caceres, a renowned environmentalist whose family has labeled her killing an assassination.

More than 1,000 people gathered as Caceres's coffin was turned over to her family at a labor union headquarters, erupting into shouts of "Justice!"

The latest protest came less than a day after demonstrators clashed with riot police in the capital Tegucigalpa following news that Caceres had been shot dead in the early hours of Thursday at her home in the western town of La Esperanza.

A mother of four who would have turned 45 Friday, Caceres rose to prominence for leading the indigenous Lenca people in a struggle against a hydroelectric dam project that would have flooded large areas of native lands and cut off water supplies to hundreds.

She persevered in her activism despite receiving numerous death threats, winning the 2015 Goldman Environmental Prize, considered the world's top award for grassroots environmental activism.

Her killing has drawn international condemnation, including from the United Nations, the United States and many environmental activists.

Washington late Friday demanded a thorough probe into Caceres's death.

"The United States condemns the murder of civil society activist Berta Caceres and calls upon the Honduran government to conduct a prompt, thorough, and transparent investigation and to ensure those responsible are brought to justice," a State Department release said.

"We offer our sincere condolences to her family, friends, and the people of Honduras, who have lost a dedicated defender of the environment and of human rights. We offer again the full support of the United States to help bring the perpetrators to justice."

Oscar winner Leonardo DiCaprio, an ardent environmentalist, wrote on Twitter: "Incredibly sad news out of Honduras. We should all honor the brave contributions of Caceres."

A coalition of more than 40 human rights groups from across the Americas called for an "independent, impartial" investigation to bring the perpetrators to justice.

The activist's family has accused the authorities of trying to mask her death as a random murder, insisting that she was assassinated because of her activism against environmental destruction by large mining and hydroelectric companies.

The organization founded by Caceres, the Civic Council of Indigenous and People's Organizations (COPINH), meanwhile said other members had received death threats from self-described hitmen allegedly hired by energy company DESA, whose hydroelectric project the group is fighting.

"In the past six months, Berta had been the target of constant, intensifying threats, shots fired on her car, and verbal and written threats from the army, the police, the mayor (in the project site) and DESA," the organization added.

Caceres's body was being transported Friday from the capital back to La Esperanza, where she was to be buried Saturday.

Activist groups from seven different indigenous ethnicities said their members would march at the burial to demand justice.