Venezuelan student activists are using new tactics to draw attention what they call political persecution by President Hugo Chavez.
Three university students chained themselves to the gates of Brazil's embassy in Caracas on Monday, seeking support for an investigation by the Organization of American States.
The commission has already invited a student delegation to Washington, but it must receive authorization from Venezuela's government before it can visit the country.
A local human rights group estimates 2,000 Chavez opponents have gone to trial in seven years on charges stemming from participation in street demonstrations and roughly 40 remain in prison.
The students unchained themselves after seven hours.