RIO DE JANEIRO, Brazil — Three French nationals working with a non-profit group that helps poor Brazilian children were stabbed to death yesterday in the organisation’s headquarters near Copacabana beach. The three suspects decapitated one of their victims, police said.After hearing screams from the third floor office and calling police, a doorman at the building captured an accountant recently accused of bilking money from the group trying to flee with a safe, said police inspector Marcus Castro. Officers arrested two more suspects within hours.

Castro identified the victims as Delphine Douyere, 36, and Christian Doupes, 42, the directors of Terr’Ativa — roughly translated as Active Earth — and organisation employee Jerome Faure, 38.

The accountant, Tarsio Wilson Ramires, 25, was allowed into the building about 7.30 a.m. because he was an employee of Terr’Ativa and brought the other two suspects with him.

After arriving at the group’s third floor offices, the three donned masks and put on surgical gloves, then called Faure to come downstairs from his 10th floor apartment in the same building, Castro said.

Faure was tied up in a chair, and may have been tortured, when the suspects decided to call Douyere and Doupes down from their ninth floor apartment, Castro said.

A struggle erupted after the couple arrived, and they were stabbed to death. The suspects then decided to kill Faure, decapitating him and leaving pools of blood on the floor and blood spattered on the walls, Castro said.

Officers found an ID card for Luis Gonzaga Goncalves de Oliveira, 27, at the scene, and arrested him at a hospital where he was seeking treatment for a knife wound. The third suspect, Jose Michel Goncalvez Cardoso, 25, was arrested later after he showed up for work in another part of the city.

Douyere had recently discovered that Ramires was stealing money from Terr’Ativa, confronted him about it, and the accountant had promised to return the money, Castro said.

Douyere and Doupes’ two-year-old son, Max, was in their apartment with a nanny when the killings happened.

The attack was the latest grisly crime in a city that has been hit by successive waves of brutal killings over the last several months.

But most of the violence has been confined to Rio’s vast shantytowns, and the killings of the French nationals happened in an upscale art deco building less than a block from the beach.

The couple used to live in a colonial neighbourhood on one of Rio’s steep hills, but had moved into the building where their office was located because they thought Copacabana was safer, said Nicholas Haber, a restaurant owner who knew Douyere and Doupes for five years.

“They were good people who worked to help people,” Haber said. “She used to pass by everyday with her boy in the stroller, and say, ‘Bonjour.”’

Police lined up the suspects in front of reporters and photographers during a press conference, and they blamed each other for the killings. Detectives will ask prosecutors to charge them all with murder, Castro said.

Terr’Ativa is a non-governmental organisation working to improve education for children and adolescents from poor communities. The group’s website said it started operating in Brazil in 2000.