U.S. and Australian authorities hacked into an app used by criminals to read millions of encrypted messages, leading to hundreds of arrests of suspected organised crime figures in 18 countries, Australian officials said on Tuesday, writes Euronews.

“Operation Ironside” by Australian police and the U.S. Federal Bureau of Investigation ensnared suspects in Australia, Asia, South America and the Middle East involved in the global narcotics trade, the officials said.

Australian Prime Minister Scott Morrison said the operation “struck a heavy blow against organised crime - not just in this country, but one that will echo around organised crime around the world”.

“This is a watershed moment in Australian law enforcement history”, - Morrison told reporters in Sydney.

Australian Federal Police Commissioner Reece Kershaw said police raids in 18 countries netted hundreds of suspects. Europol and the FBI said on social media they would hold news conferences later on Tuesday.

Australia said it had arrested 224 people, including members of outlawed motorcycle gangs, while New Zealand said it had detained 35 people.