Belgium on Saturday raised its terror alert in the Brussels region to the highest level, warning of a "very serious" and "imminent" threat. The metro will be shut till Sunday and the public has been warned to avoid crowds, a statement said, as reported by the BBC. Apart from Brussels, the rest of Belgium stays at a lower level of threat of “still serious”. AFP reported that Turkey had detained a Belgian citizen believed to have links to the Paris attacks.

Some of the suspected Paris attackers who killed 129 people in last week’s gun and bomb violence are suspected to have made Brussels their hideout. One of those being sought, Salah Abdeslam, is believed to have gone back to Belgium. The Islamic State had claimed responsibility for carrying out the attacks. On Friday, the United Nations Security Council unanimously resolved to "redouble" action against Islamic State.