Eleven Brazilian policemen were arrested for suspected involvement in the massacre of 30 people last week on Rio de Janeiro's outskirts, local authorities said on Monday.

Four police officers arrested earlier were charged with murder for a shooting spree last Thursday night, while the seven others were linked to the mass killing and have been remanded to police barracks, local media quoted Marcelo Itagiba, the Rio State security secretary, as saying.

The four alleged murderers were identified by eyewitnesses. Two of them were recognized as members of a death squad who committed the massacre and the other two are still under investigation, according to Rio State Police Chief Alvaro Lins.

Meanwhile, police said they continued the search Monday for another suspect in the shooting spree.

On Thursday night, several masked gunmen opened fire apparently at random from two moving vehicles on citizens in Baixada Fluminense, a suburb on Rio's north side.

A total of 30 people were killed, including three children aged from 7 to 13. The shootings began with the killing of 18 people at a bar in the town of Nova Iguacu. The gunmen then drove to the neighboring town of Queimados where 12 passers-by were shot dead.

After the worst blood bath in years, President Luiz Inacio Lulada Silva ordered Brazil's federal police to participate in the investigation. Lula reassured the families of the victims in a radio program Monday that all of the killers will be arrested. The police offered US$2,000 in rewards to anyone who could provide clues of the wanted.

The previous worst mass murder in Rio history happened in 1993,when a death squad formed by police officers massacred 21 people in the slum of Vigario Geral.

Death squads, often made up of off-duty or retired officers, were believed to be hired by local businessmen to kill undesirables.

(Xinhua News Agency April 5, 2005)