If you thought malware was the only reason not to put an unidentified USB drive into your computer, think again.

Ecuadorian journalists have been targeted with exploding USB sticks in an incident press freedom advocates have called “a new escalation of violence against the press” in the South American country.

At least five journalists from news outlets including TV and radio stations were sent envelopes earlier this week which contained drives that were rigged to detonate when plugged into a USB port.

Political journalist Lenin Artieda was the only one to have sustained minor injuries in the attacks, suffering minor scratches on his hand and face.

Local chief of police Colonel Xavier Chango said the device had a small explosive charge but thankfully only half of it detonated when Artieda plugged the device, according to freedom of speech organisation Fundamedios.

“We presume that it was [explosive] RDX and we are going to do the corresponding analysis,” he said.

Some of the letters contained direct threats to the journalists, while another was offering information that would “unmask” the leftist political faction named after former Ecuadorian president Rafael Correa.

“If you think it's helpful, we can come to an agreement and I'll send you the second part,” the letter said.

But when journalist Milton Pérez plugged the USB into a computer it didn’t explode, likely because it wasn’t connected properly.

Morning radio host Miguel Rivadeneira also received a device in the mail along with “a very confusing message”. He handed it to his producer who plugged the USB into a PC through an adapter and found nothing was written on it.

Hearing about the explosion at a different media outlet, they brought it to the police who found explosive material and suggested that the different charge in the adapter saved the office from an explosion.

Authorities have traced the letters’ origins from the coastal town of Quimsaloma and are investigating what the prosecutor’s office has described as an act of terrorism.

As per CBS, the government has said it “categorically rejects any form of violence perpetrated against journalists and media outlets” and described the intimidation tactics as “repugnant”.

Fundamedios said the attacks were “worrying, unacceptable” and that “violating freedom of expression … requires immediate state intervention”.

Ecuador is in a state of instability with the president last year announcing a crackdown on drug gangs following attacks on police officers and gang-related bombings.

Media outlets have been quite literally caught in the crossfire. In October, a TV network was attacked in a shooting linked to a drug cartel and which saw the perpetrators leave death threats against a newspaper director warning him not to distribute the news to certain outlets.