Journalists at two news outlets in Ecuador have been sent envelopes containing electronic devices fitted with explosives, the attorney general said on Monday.
The explosion at Ecuavisa television in Guayaquil, which police said was partial, occurred when journalist Lenin Artieda plugged the device into his computer. He suffered minor injuries.
"It's a military-type explosive, but very small capsules," said Xavier Chango, the national head of forensics.
Police carried out a controlled detonation of a device sent to the news department of TC Television, also in Guayaquil.
There were also alerts raised at two media outlets in Quito, Chango said.
The government said it would defend freedom of expression in the country.
"Any attempt to intimidate journalism and freedom of expression is a loathsome action that should be punished with all the rigor of justice," it said in a statement.
President Guillermo Lasso has blamed rising violence, including within the prison system, on competition between drug trafficking gangs for territory and control.
Ecuador is used as a transit point for cocaine being moved to the United States and Europe.
(Reporting by Alexandra Valencia; Writing by Julia Symmes Cobb; Editing by Alison Williams)