People are angry because Facebook hasn't activated its 'Safety Check' feature yet after the deadly Brussels attacks

People are calling on Facebook to activate its "Safety Check" features after a series of apparent terrorist attacks in Brussels have killed at least a dozen people and brought the city to a standstill.

On Tuesday morning, there were two explosions at an airport in Brussels, Belgium - as well as further explosions at city Metro stations. 13 are reportedly dead, and dozens more are injured.

There have immediately been calls for Facebook to activate its "Safety Check" feature, a tool that allows people in the area to check themselves in as safe following natural disasters or terror attacks. (The Independent previously reported on these calls.)

It was activated in Paris following the deadly terror attacks in November 2015 - the first time it was used in the aftermath of a non-natural disaster. Since then it has been activated following attacks in Nigeria and Ankara, Turkey.

But around two hours after the Brussels attacks, it's not yet active in Belgium - prompting some frustration. There are multiple reports that phone lines and mobile networks are being overloaded, making it difficult for people to contact loved ones to check they are safe.

Facebook did not immediately respond to a request for comment. It's possible that the social network is waiting to be sure there is no risk of further attacks in the city before activating the feature.