Facebook has activated its Safety Check feature for those caught up in the Brussels attack, which has left up to 10 dead.
If you have friends and loved ones in Brussels who are using the feature, your notifications should light up with the following green icon.
The switch follows calls from concerned social media users desperate to contact family and friends as reports emerged of mobile networks getting saturated.
Deputy Prime Minister, Alexander De Croo, tweeted "Brussels mobile networks are getting saturated. Please contact through data messages: Facebook, WhatsApp, Twitter. Avoid calls."
"We activated Safety Check - a simple and easy way to say you’re safe and check on others after a major disaster or crisis - in Brussels," a spokesperson for Facebook told the Huffington Post via email.
"In 2015, more than 950 million people received a notification that a friend or loved one was safe in a crisis."
However, several Twitter users expressed concern over how long it took Facebook to turn the feature on.
Facebook has faced criticism in the past for its selective use of the Safety Feature.
The features allows friends to either click on an "I'm safe" or "I'm not in the area" icon and was initially introduced for natural disasters.
It also lets users know how many friends are in the affected area, number of people marked safe and those "not marked safe yet."