Mexican journalists, activists and human rights lawyers were targets of spyware, according to internet watchdog Citizen Lab at the University of Toronto.

The Citizen Lab report said the spyware was developed by Israel's NSO Group and sold to the Mexican government. The spyware targeted prominent journalists, activists and lawyers investigating suspected human rights abuses by security forces, the disappearance of more than 40 students in 2014 and alleged government corruption.

The spyware, dubbed Pegasus, sent targeted messages with links that, if clicked on, allowed their devices to be spied on.

Rafael Cabrera, editor of Buzzfeed Mexico, tweeted that he received suspicious text messages in May 2016. "In May 2016 I got these text messages. Now, we know they are malware sent by the Mexican government to extract information from my smartphone," read the tweet.

Mexico issued a statement saying it conducts intelligence operations but denied illegal spying.

"The Government of the Republic categorically denies that any of its entities carries out actions of surveillance or intercepting communications from human rights defenders, journalists, anti-corruption activists or any other person without prior judicial authorization," read the statement.

Journalists face danger in Mexico

Journalists in Mexico face the constant threat of violence and death for their reporting. Reporters Without Borders, a non-profit organization that promotes freedom of the press, confirmedfour Mexican journalists were killed so far this yearfor their reporting. That is more than any other nation, according to the organization.

Reporters Without Borders ranked Mexico as the 33rd worst country for press freedom in the world in its 2017 World Press Freedom Index. Only Cuba has a worse ranking in the Americas. Journalists there face danger due to the ongoing drug cartel battles and risks of covering potential government corruption.

kbd/rc (AP, Reuters)