One of Brazil's most wanted criminal suspects was killed in a police operation Saturday in Rio de Janeiro, police said.

Wellington da Silva Braga, better known as Ecko, was believed to command so-called militia groups in more than 20 neighbourhoods.

The police communications office said a confrontation erupted when officers arrived at a house to try to arrest Braga. He was wounded and pronounced dead at a local hospital.

The Civil Police of Rio reported that Braga was hit by one shot during the operation and by a second, in the heart, when he was being transferred to the hospital and tried to take a gun from a police officer.

There were no immediate reports of other injuries or arrests.

Braga faced charges of extortion, criminal association, homicide, receiving stolen goods, money laundering and carrying weapons, though he had never been arrested.

The militia groups, usually based on former police officers, soldiers and firefighters, initially formed to combat criminal gangs in poor neighbourhoods, but became deeply involved in trafficking and extortion themselves.

Police say Braga''s group is one of the three largest criminal operations in the Rio de Janeiro region.