AFP/Brasilia

Amid increasingly tense protests just four months before Brazil hosts the World Cup, Santiago Andrade was struck on the head by a flare thrown by a demonstrator in Rio a week ago, and died of his injuries on Monday.

A 23-year-old man suspected of throwing the flare was arrested in northern Brazil. He faces up to 35 years in prison.

The suspect told police that he has already been “asked to participate in protests in exchange for payment.”

The most radical protesters, many of them poor or working class, also sometimes receive food and transport fares to travel to the demonstrations, Caio Silva de Souza said in his police statement made public by tabloid Extra.

Many Brazilians are angry that the cost of living is rising inexorably, services remain poor and yet the country is spending billions on hosting the World Cup in June and the 2016 Rio Olympics.

Critics have suggested that hard-left parties paid disaffected young radicals to turn up and stoke social tension in the run-up to June’s World Cup and October elections. Some leftist marchers responded to that by brandishing a banner reading: “I didn’t get a real; I am here for an ideal.”

Police estimated the crowd at 500, while organisers said they numbered 2,000. A strong police contingent barred protesters from entering Central Station, the largest railway station in Rio.

De Souza did not say if he had actually received cash but his lawyer indicated some marchers had been offered 150 reais ($60) to “foment violence” and “destabilise the government.”

The inducements are sizable in a country where the minimum wage is just 724 reais per month. The Andrade suspect also pointed to radical leftist parties, such as the Socialism and Freedom Party, or PSOL, and the United Socialist Workers Party, or PTSU.

Rio Governor Sergio Cabral has suggested political parties were sponsoring some of the violence. Leftist Rio state lawmaker Marcelo Freixo, who has fought ardently against far-right militias, denied claims he was linked to people involved in Andrade’s death. But Freixo said he and his colleagues should have made clearer their opposition to radical groups known as black blocs who have gate-crashed what were originally peaceful protests.

“There is political manipulation in the marches, infiltration to stir up trouble - but they come from the right not from the left,” history teacher Diego Medeiros said.

Protesters have indicated they will keep on marching right up to and during the World Cup, prompting security concerns.

Last year’s Confederations Cup in Brazil was marred by huge demonstrations drawing more than a million people nationwide. However, tournament organisers and world football body FIFA say they have full confidence in an integrated security system across the 12 venues.

Amid rising tensions, politicians turned to the thorny issue of whether to seek to enact new anti-terrorism legislation.