The bodies of 39 people have been found in a lorry container at an industrial estate in Essex.
Police officers were called by the ambulance service shortly before 1.40am on Wednesday following the discovery of the container with people inside at Waterglade Industrial Park in Eastern Avenue, Grays.
Essex Police said the vehicle travelled from Bulgaria and entered the UK through Holyhead, Anglesey, on Saturday.
The force confirmed that 38 adults and one teenager found in the lorry have died without confirming whether any survivors were found in the lorry.
A murder investigation has been launched into the incident. The lorry driver, a 25-year-old man from Northern Ireland, has also been arrested on suspicion of murder.
“We are in the process of identifying the victims, however I anticipate that this could be a lengthy process,” Chief Superintendent Andrew Mariner said in a statement.
“We have arrested the lorry driver in connection with the incident who remains in police custody as our enquiries continue,” he added.
Prime Minister Boris Johnson expressed shock over the incident in a series of messages on Twitter.
I’m appalled by this tragic incident in Essex. I am receiving regular updates and the Home Office will work closely with Essex Police as we establish exactly what has happened. My thoughts are with all those who lost their lives & their loved ones.
— Boris Johnson (@BorisJohnson) October 23, 2019
In June 2000, 58 Chinese immigrants were found suffocated to death in the back of a lorry in Dover. There were two survivors.
A Dutch lorry driver was jailed the following year for manslaughter.