G7 countries and tech giants including Google, Facebook and Twitter on Friday agreed to work together to block the dissemination of extremist Islamist content on line, Italy announced.

"These are the first steps towards a great alliance in the name of freedom," Interior Minister Marco Minniti said after a two-day meeting with his Group of Seven counterparts, stressing the importance of the internet for extremist "recruitment, training and radicalisation."

Officials said the accord aimed at removing jihadist content from the internet within two hours of being posted.