Requena is just downriver from Leticia, Colombia and Tabatinga, Brazil, two port cities that are the gateways to enter the remote corners of both countries.
Valderlei Canuto Leandro, 32, host of the Sinal Verde (Green Signal) programme on Radio Frontera, was shot dead by unidentified assailants in the city of Tabatinga, in the state of Amazonas, according to local press reports.