Brussels bomb attacks - how the events unfolded throughout the day
Here is how events unfolded on Tuesday as Brussels was targeted by terrorists.
*At around 7am a double blast hits the city's Zaventem Airport. Passengers are evacuated and within the hour police say at least one person has been killed. People are advised to stay away from the airport.
*About an hour later, during the morning rush hour, a bomb explodes on a subway train at Maelbeek Metro station.
*Reacting to the news from Brussels, Prime Minister David Cameron says he is "shocked and concerned by the events in Brussels", adding: "We will do everything we can to help."
*French President Francois Hollande holds an emergency meeting. The Brussels attacks come days after the arrest of Salah Abdeslam, suspect in the Paris attacks of November last year in which 130 people were killed.
*Mr Cameron announces he will chair a meeting of the Government's emergency Cobra committee in response to the attacks.
*Just before 9.15am it is announced that London Gatwick airport has increased its security following the Brussels explosions.
*Around 20 minutes later Eurostar says it has suspended services to or from Brussels Midi station.
*Within an hour the UK's most senior counter-terrorism officer Mark Rowley says police forces across the UK have increased their presence at key locations as a precaution in the wake of the attacks.
*The Belgian prime minister Charles Michel says: "What we feared has happened, we were hit by blind attacks."
*At midday Mayor of London Boris Johnson, who attended the Cobra meeting, tells reporters there may be a British casualty. Within the hour Downing Street confirms a Briton was injured at the airport in Brussels.
*By early afternoon the death toll is said to have reached 34. As the day continues the number of people injured rises to almost 200.
*US President Barack Obama sends a message of support to the people of Brussels, saying: "We can and we will defeat those who threaten the safety and security of people all around the world."
*Around 3.30pm, more than eight hours after the first blasts, the Islamic State terror group claims responsibility for the attacks, saying their members detonated suicide belts.
* Around 4.30pm an official says a third bomb at Brussels airport has been deactivated.
* Less than an hour later Belgian police issue a CCTV picture of a man who is suspected of carrying out the attack at Brussels airport.
* By 5.30pm, eyewitnesses in the Schaerbeek district in north-east Brussels reported a major police operation focusing on the train station. They reported a cordon being put in place and anti-bomb vehicles at the scene.
* Later, at 5.45pm, prosecutor Eric van der Sypt confirmed two suicide bombers died in the attack on the main airport in Brussels and a third was being "actively" sought.
* The Belgian prime minister Mr Michel held a press conference to confirm there will be three days of national mourning.
* King Philippe of Belgium says he and Queen Mathilde "share the pain" of all those who suffered in the attacks. In a televised address to the nation, he calls on Belgians to stay "confident" in the face of terror.
* Shortly after 6pm, prosecutors confirm the discovery of a new explosive device containing nails during a specialist search. Chemical products and an Islamic State group flag are also found in the raid.
* As night falls on Belgium, at 6.50pm, prime minister Mr Michel lights a candle during a vigil at Place de la Bourse, the city's stock exchange building.
* Afterwards, Zaventem mayor Francis Vermeiren tells reporters the suspects "came in a taxi with their suitcases, their bombs were in their bags". He adds: "They put their suitcases on trolleys, the first two bombs exploded. The third also put his on a trolley but he must have panicked, it did not explode."
* The Government announces it will hold a minute's silence at 11am (GMT) on Wednesday.
* Early on Wednesday morning Belgian state broadcaster RTBF names the two suicide bombers who struck at Zaventem Airport as brothers Khalid and Brahim El Bakraoui, from Brussels.
* The third suspect, who is being actively sought by police, is named by local media as Najim Laachraoui. The 24-year-old is also suspected of being responsible for the bombs used in the Paris massacre in November after his DNA was found on suicide belts used in the Bataclan theatre and the Stade de France.
* Shortly before 10am on Wednesday, local media in Belgium reports that Laachraoui has been arrested in Anderlecht.
* At around 10.30am Downing Street says it is concerned about one missing British national following the Brussels attack, adding that four Britons had been injured, three of whom are in hospital.
* A No 10 spokesman says they are no longer advising against travel to Brussels, but British nationals in Belgium should remain alert and vigilant.