MEXICO CITY (Reuters) - Two-thirds of Mexicans reject offering an amnesty to members of criminal gangs as a way of reducing violence in the country, a poll showed on Monday, days after a top leftist presidential candidate floated the idea of exploring the step.

At the start of December, Andres Manuel Lopez Obrador told supporters in the violence-wracked state of Guerrero he was prepared to analyze all the options, including an amnesty, to bring peace to Mexico after years of violence between gangs.

“You can’t fight fire with fire,” he said.

Asked by a reporter whether his amnesty could include drug cartel bosses, Lopez Obrador his campaign would “consider it” in a recording published by newspaper El Universal.

A telephone survey by polling firm Buendia & Laredo for El Universal showed only 23 percent of the respondents agreed somewhat or strongly with the idea of brokering an amnesty with the gangs in exchange for pledges to reduce violence.

Some 66 percent took the opposite view, while eight percent said they had no opinion either way. The rest gave no answer.

Violence between drug cartels and security forces has been blamed for well over 100,000 deaths in the past decade, and Mexico is on track to register its highest murder total this year since it began keeping regular monthly tallies in 1997.

Lopez Obrador, who has led most of the early polls for the July 2018 election, did not provide details about the potential scope of the amnesty, and aides to the 64-year-old consulted by Reuters have so far declined to flesh out how one might work.

A former mayor of Mexico City, Lopez Obrador was runner-up in the last two elections, and his adversaries seized on the amnesty to paint the proposal as a threat to security and an affront to the victims of organized crime.

A gang truce in El Salvador in 2012 initially cut violence, but when it broke down, murders soared to new heights.

The Buendia & Laredo survey, which polled 600 people Dec. 7-8, said that only 16 percent of those polled felt the amnesty would improve the security situation in Mexico, while 62 percent took the opposite view. Some 18 percent believed it would make no difference and the rest gave no answer.

The poll was conducted had a margin of error of 4.0 percentage points, El Universal said.