People who manufacture weapons or even so much as invest in the arms industry are hypocrites if they call themselves Christian, said Pope Francis at a rally on Sunday, Reuters reported.

"If you trust only men you have lost," he told the young people who attended the rally whilst talking about war, trust and politics, after he put aside the speech he had prepared.

"It makes me think of ... people, managers, businessmen who call themselves Christian and they manufacture weapons. That leads to a bit of distrust, doesn't it?" His statements were met with a roar of applause from the crowd, according to The Guardian.

Pope Francis then went on to criticize people involved in the arms business, saying "duplicity is the currency of today ... they say one thing and do another." He further added on to comments he has made in the past regarding events that transpired during the world wars, talking about the "tragedy of the Shoah," using the Hebrew term for the Holocaust.

"The great powers had the pictures of the railway lines that brought the trains to the concentration camps like Auschwitz to kill Jews, Christians, homosexuals, everybody. Why didn't they bomb (the railway lines)?" he said.

He also addressed "the great tragedy of Armenia" avoiding the use of the word "genocide" which caused Turkey to recall its ambassador to the Vatican earlier this year.

This is the Pope's toughest condemnation of the weapons industry, but it's not the first time he has denounced those involved in the business. Last year, he criticized arms dealers saying that they "fabricate death" and referred to them as "merchants of death" who "make death into a trade," according to the Wall Street Journal.