A lorry driver has appeared in court charged with the manslaughter of 39 people found dead in a refrigerated trailer in Essex.
The bodies were found in the container in the early hours of Wednesday on an industrial estate in Grays.
Maurice Robinson, of Northern Ireland, was remanded in custody at Chelmsford Magistrates’ Court.
Writing in a book of condolence, Prime Minister Boris Johnson said the world had been “shocked by this tragedy”.
Mr Robinson, of Laurel Drive in Craigavon, appeared via video-link and is charged with 39 counts of manslaughter, conspiracy to traffic people, conspiracy to assist unlawful immigration and money laundering.
He will next appear at the Old Bailey on 25 November.
DNA tests are being carried out in Vietnam to help to identify the dead.
Mr Johnson was joined at Thurrock Council’s offices by Home Secretary Priti Patel and members of the emergency services.
They also paid their respects to the victims by laying flowers in the nearby Mulberry garden.
Writing in the book of condolence, the prime minister said: “The whole nation, and indeed the world had been shocked by this tragedy and the cruelty of the fate that has been suffered by innocent people who were hoping for a better life in this country.
“In condemning the callousness of those responsible for this crime, we in the government of the United Kingdom resolve to do everything in our power to bring the perpetrators to justice.”
Three other people arrested in connection with the deaths were released on bail on Sunday.
A man in his 20s, who was arrested by Irish police in Dublin on Saturday, was said to be “of interest” to the Grays investigation.
His arrest at Dublin Port is unconnected to the lorry death investigation but Essex Police said they were liaising with Irish police, as the man “is currently held outside the jurisdiction of the law of England and Wales”.
Detectives in Essex are now working on the largest mass fatality victim identification process in the force’s history.
Initially, police said the 31 men and eight women were Chinese but a number of Vietnamese families have described how they fear their loved ones are among the dead.
Some of the victims are said to have paid thousands of pounds to guarantee their safe passage to the UK, from where they would be able to carry out work that would give them money to send home.
Reuters reports that the UK government has sent documents to Vietnam’s Ministry of Public Security in a bid to identify four of the 39 victims.
Families in the country have shared their fears their loved ones could have been among those who died.
Pham Thi Tra My, 26, sent her family a message on Tuesday night, saying her “trip to a foreign land has failed”.
Meanwhile, Nguyen Dinh Gia said he had not heard from his son Nguyen Dinh Luong, 20, since he told him last week he was trying to join a group to get from Paris to the UK.
Detectives are also investigating claims the lorry could have been part of a convoy of three carrying about 100 people.