Brussels blasts: Crisis information

Scores of people were killed in blasts at Zaventem airport and Maelbeek metro station in central Brussels

Public transport networks in Brussels were closed and security tightened across Europe after deadly attacks on the Belgian capital's international airport and a city metro station. Here is a list of transport networks disrupted and advice to travellers, including hotline numbers.

• Belgium has increased its terror threat level to four for the whole country

• Security has been stepped up at nuclear facilities in Belgium

• The Brussels airport authority says all airport operations are suspended for the rest of Tuesday. Zaventem airport - scene of one of the attacks - will remain closed on Wednesday

• Buses, trains and trams stopped running and metro stations were closed for much of the day, although most public transport services were starting to operate again by late afternoon

• Rail operator SNCB is tweeting which Brussels train stations are reopening. The Brussels Crisis Center, in its advisory, said buses and trams and Metro lines 2 and 6 were opening.

• But travellers have been warned to expect long delays

• The Crisis Center has told people they no longer need to stay inside, having earlier said people should stay where they were and not travel. But people have been urged to stay vigilant

• Children, who had been told to stay inside school buildings, were later allowed to go home. Schools are expected to open as normal on Wednesday

• The Flemish-speaking Free University of Brussels (VUB) is to close for the rest of the week after a security alert there during which a controlled explosion was carried out

• In the immediate aftermath of the attacks, the Crisis Center asked people to communicate via text or social media because the mobile phone network had become overloaded. Although networks are operating normally again, people have been urged to continue communicating by text

• Eurostar trains between Brussels, Lille and London stopped running to or from the Belgian capital. Eurostar says it hopes to resume a full service on Wednesday.

• Thalys trains connecting Brussels with Paris and Amsterdam were also "deeply disrupted" but appear to have some services operating again

• Soon after news of the attacks broke, the European Commission told its staff to stay inside their offices or not to come to work

• All EU institutions were put at alert level orange, with all meetings cancelled and access to buildings only for staff with ID badges

• Britain and France advised people to avoid crowded places in Brussels. The UK's Foreign Office has warned Britons against travel to Brussels

• Security has also been tightened at Charles de Gaulle airport in Paris, Germany's busiest hub Frankfurt and at airports in the Netherlands and the UK

• France has deployed 1,600 extra police to its borders and transport networks

• There were reports of long queues of traffic at the Belgian border with the Netherlands. Dutch counter-terrorism officials had said they would carry out extra border checks

• Germany has increased checks on its borders with Belgium and France

• A helpline has been set up for anyone concerned about people they know who were due to use Zaventem airport. The number is [phone]

• For those in Brussels, the Crisis Center has set up an emergency hotline on 1771 but has asked that only those concerned about family and friends call

• Britain's Foreign Office has set up a helpline for people in the UK on 02070080000

• Facebook has activated a "safety check" button for people in Brussels to reassure loved ones that they are safe

Facebook has activated a "safety check" button for people in Brussels