Twitter, Google, Instagram and Telegram were involved in the operation, Europol said.
An operation led by Europe's policy agency has shut down a number of Islamic State-linked servers, dealing a "severe blow" to the propaganda arm of the jihadist group.
Europol said on Monday the operation had closed accounts associated with the group's news outlet - Amaq News - after a days-long examination of "propaganda videos, publications and social media accounts supporting terrorism and violent extremism."
"For the time being, for as far as we know, IS is not present on the internet anymore. And we will see how fast, if ever, they will regain surface," said Eric Van Der Sypt, a spokesman for the Belgian prosecutor's office.
He also went on to highlight the importance of tackling the group's online presence just as much as on the physical battlefield.
"Besides the military activities on battlefields in Syria and Iraq and the attacks on European territory, Islamic State conducts a huge battle on the world wide web - in the form of propaganda coordinated by the IS media network."
"All attacks on our country," he added, "were claimed in publications at that time by Amaq."
Europol had confirmed in an earlier statement that a large swathe of propaganda material had been found on the Telegram app, and assistance from the network had led to a "significant portion of key actors" in the IS network being "pushed away from the platform".
The agency later praised the app for assisting to "root out...malicious content".
Telegram is just one of nine platforms Europol collaborated with for the operation, including Google, Twitter, Instagram and Telegram.