FILE PHOTO: Pope Francis speaks with media on the plane as he travels from Poland back to Italy, July 31, 2016. REUTERS/Stefano Rellandini/File Photo

VATICAN CITY (Reuters) - If you ever wondered how to say “fake news” in Latin, it’s “nuntii fallaces” - and Pope Francis is writing a document on just that.

Francis announced it himself in a tweet to his nearly 40 million followers on Friday, saying the theme of his message for the Roman Catholic Church’s next World Day of Social Communications will be “The truth will set you free. Fake news and journalism for peace.”

In Latin, one of the nine languages the pope uses to tweet, that would be “Veritas liberavit vos. Nuntii fallaces et diurniariorum opus ad pacem.”

A Vatican statement said the issue was important enough for the pope to address because “fake news contributes to generating and nurturing a strong polarisation of opinions.”

A distortion of facts, it said, can have “repercussions at the level of individual and collective behaviour.”

Francis said in an interview last year that media that focus on scandals and spread fake news to smear politicians risk becoming like people who have a morbid fascination with excrement.

The Vatican statement said the leader of the 1.2 billion member Church wanted to offer “a reflection on the causes, the logic and the consequences of disinformation in the media, and helping to promote professional journalism, which always seeks the truth”.

The Church’s next World Day of Social Communications will be celebrated on May 13. The pope’s message will be released on January 24, feast of St Francis de Sales, the patron of journalists.

(This version of the story corrected day of Day of Social Communications to May 13 from Jan. 24).