The bodies of 39 people have been found in a lorry in Essex. The vehicle came into the UK from the Belgian port of Zeebrugge, according to police.
How many migrants have died in transit in the UK?
Before this tragedy, five people had been found dead in or on lorries or containers in the UK, since figures started being collected, in 2014.
It is thought they died while being smuggled to their intended destination or after stowing away.
- 2014: An Afghan migrant was found dead at Tilbury Docks, Essex. He was in a shipping container, with 34 Afghans who survived
- 2015: Two migrants were found dead in a wooden crate in a warehouse in Branston, Staffordshire. The crate had been sent from Italy in a container
- 2016: An 18-year-old migrant was crushed clinging to the underside of a lorry in Banbury, Oxfordshire
- 2016: A body was found in the back of a lorry in Kent, which had travelled from France
Data was not collected in the same way before 2014, but these kind of tragedies are not new.
In 2000, 58 Chinese migrants were found suffocated in a lorry at Dover. The driver was found guilty of manslaughter and sentenced to 14 years in jail.
How do people arrive illicitly in the UK?
Since the closures of migrant camps in France, in 2016-17, there have been fewer “opportunistic” attempts to enter the UK by individuals.
But more Channel crossings are being co-ordinated by organised criminal gangs, according to the UK’s National Crime Agency.
And during 2018, there was an increase in “higher risk methods of clandestine entry”.
This includes transporting people in containers and refrigerated heavy goods vehicles.
What is security like?
The UK, France and Belgium have an agreement to conduct immigration checks on certain cross-Channel routes – before vehicles board ferries.
Searches on vehicles include the use of scanners, which can detect hidden products as well as people.
This takes place before vehicles board ferries, and has led to the discovery of people concealed in lorries and containers.
The lorry container in which 39 people were found dead in Essex arrived in the UK through the nearby port of Purfleet.
Police say it had arrived from Zeebrugge, which is a popular route for people smuggling.
The National Crime Agency has also pointed out that smugglers have been using “less busy” ports in the UK, including Purfleet, Hull and Tilbury.
A 2016 report from the UK’s border inspectorate raised concerns about staffing and resources, including vehicle scanners, in the east of England.
How many people have been arrested?
By its nature, it is difficult to determine the true scale of people smuggling, since a proportion of it will go undetected.
Police forces do compile figures on people arrested for illegally entering the country but these are not routinely published.
A BBC News investigation found there had been 27,860 arrests for illegally entering the UK between 2013 and April 2016. Arrests rose by 25% during that time.
In the same period, there were 2,482 arrests for facilitating illegal entry.
How many deaths have there been elsewhere in Europe?
The UN’s International Organisation for Migration started recording deaths such as these in 2014, following a surge in migration to Europe from the Middle East.
In 2015, 71 people suffocated in the back of a lorry in Austria.
Other incidents have seen vehicles smuggling migrants involved in serious accidents, such as a 2016 minibus crash that killed nine people from Pakistan and Afghanistan.
The UN estimates 491 people have died or gone missing crossing Europe since early 2014.
The most common causes of death are car and train accidents. About 10 people have been killed in or around the entrances to the Channel Tunnel.
The numbers are collected through a mixture of charity, international organisation and media reports. They do not include deaths in migrant camps or detention centres.
Nor do they include the estimated 18,500 people who have died, or gone missing, crossing the Mediterranean.
A note on terminology: The BBC uses the term migrant to refer to all people on the move who have yet to complete the legal process of claiming asylum. This group includes people fleeing war-torn countries, who are likely to be granted refugee status, as well as people who are seeking jobs and better lives, who governments are likely to rule are economic migrants.