#brusselsLockdown

As Brussels enters its third day under its highest terrorism alert level, a request from authorities not to disclose details about police activity on social media has sparked an innovative response from Twitter users.

Cat pictures have inundated the hashtag #BrusselsLockdown in an attempt to make it harder for suspects to uncover information about anti-terror measures, after Belgium police asked social media users to stop tweeting details of a police operation on Sunday evening that could have alerted suspects.