Timeline: how terror came to Brussels

15 January 2015: Soon after the Charlie Hebdo attacks in Paris, Belgian police shoot dead two terrorists in Verviers. Other suspects are arrested after raids in Brussels and surrounding towns.

Belgian officials say more than 300 people have left Belgium to join jihadi groups in Syria and Iraq.

13 November 2015: Three teams of terrorists carry out co-ordinated attacks on the Bataclan music venue, the Stade de France and restaurants and bars in Paris, killing 130 people.

16 November 2015: Belgian anti-terror police raid a house in Molenbeek, an impoverished suburb of Brussels that is home to many North African immigrants. No one is arrested.

French interior minister Bernard Cazeneuve says: “The wretched attacks were prepared abroad and mobilised by a team of actors living on Belgian territory.”

18 November 2015: Police raid a flat in the Paris suburb of Saint-Denis. After a lengthy gun battle they shoot dead Abdelhamid Abaaoud, the Belgian suspected ringleader of the Paris attacks, along with a female cousin.

Another Moroccan-Belgian man, Chakib Akrouh, who helped attack restaurants in Paris, blows himself up.

21 November: Brussels is in “lockdown”, with shops, schools and public transport closed after the security services receive information about an imminent threat, possibly a Paris-style string of co-ordinated attacks.

22 November: Belgian police make 22 raids across the country and arrest 16 terror suspects, but supected Paris gunman Salah Abdeslam remains on the run. Police find a suicide belt, possibly discarded by Abdeslam, in the Paris suburb of Montrouge.

CCTV footage from 11 November, 2015 shows Salah Abdeslam (R) and Mohamed Abrini (L) shopping in a petrol station north of Paris.

24 November: Belgian authorities issue an international arrest warrant for 30-year-old Mohamed Abrini, another alleged Paris gunman. He and Abdeslam are now the prime suspects. Nine other men who took part in the attacks are dead.

10 December 2015: Salah Abdeslam’s fingerprints are found during a raid on an apartment in Schaerbeek, Brussels, along with suicide belts and explosives.

13 January: Belgian investigators identify three properties in Schaerbeek, the city of Charleroi and the village of Auvelais as safe houses used by the Paris suspects before they launched the attack.

18 January: Another Belgian suspect, 26-year-old Gelel Attar, from Molenbeek, is arrested in Morocco.

15 March 2016: Police snipers shoot dead Algerian Mohamed Belkaid, reportedly an Islamic State member, after a raid on a flat in the Brussels suburb of Forest. Salah Abdeslam is believed to have been at the flat but escaped.

18 March 2016: Abdeslam is finally captured after being shot in the leg in a raid in Molenbeek after four months at large.

21 March 2016: Belgian police name Najim Laachraoui as one of two men still sought in connection with the Paris attacks. He is thought to have been a close associate of Abdeslam and Belkaid. Mohamed Abrini is also still on the run.

March 2016: Bombs go off at Zaventem airport and the Maelbeek metro station in Brussels, killing dozens of people.