There was no immediate claim of responsibility for the attacks in Brussels on Tuesday though supporters of the Islamic State praised the blasts that killed more than 30 people on social media.
“The state will force you to reevaluate your ways a thousand times before you are emboldened to kill Muslims again, and know that Muslims now have a state to defend them,” said one supporter of the terrorist group on Twitter.
Another pro-IS Twitter handle praised the attacks and warned of more strikes. A tweet that was retweeted by the Terror Monitor group read: “What a pleasure to explode an unfaithful head and even better to cut his head.”
“Expect more bombs, more death! in future also,” the pro-IS handle said.
The attacks came four days after the dramatic arrest in Brussels of Salah Abdeslam, the prime suspect in the Paris attacks claimed by the IS. Security services across western Europe had been on a high state of alert for fear of attacks backed by the IS.
Adam Schiff, the top Democrat on the US house intelligence committee, said the attacks at the airport and a metro station in Brussels bore “all the hallmarks of an ISIS-inspired, or ISIS-coordinated attack”.
Schiff’s staff said he had received a preliminary briefing from US officials on Tuesday. Schiff also said it was unclear if encrypted communications played a role in the attacks but noted that the assault occurred despite Brussels being under constant vigilance.
The US Department of Homeland Security (DHS) said it was closely monitoring the events in Brussels and “would not hesitate to adjust our security posture, as appropriate, to protect the American people”
The attacks are expected to revive national security as a key issue in the 2016 US presidential election.
Scores were also injured in the coordinated attacks -- only four days after Belgian Police arrested the suspect in the Paris terror attack which killed 130 people in November.