At least 30,000 demonstrators clashed with police Wednesday in Fortaleza, Brazil's fifth-largest city. Police fired tear gas and rubber bullets at protesters during the melee.
Protest leaders said they would try to incite more people to the street to rally against political corruption, the cost of living and the mass amount of public funds designated for the 2014 World Cup soccer tournament.
The International News Safety Institute, an organization monitoring the safety of journalists from its base in London, warned members of the press to think ahead, get their story and then move away from any demonstrations.
"The security forces will counter violence with violence, so be prepared for this," a warning published Friday said. "Try to understand and learn police tactics so you can work more safely.
INSI said at least 15 members of the press were injured or arrested by Brazilian security forces in Sao Paulo last week. A press photographer was shot in the eye with a rubber bullet. Protesters have also physically attacked members of the press.
The institute advised journalists to "know their [crowd control] weapons" and to avoid getting caught up in large demonstrations.