British police said that 39 people found dead in a truck near London are believed to be Chinese nationals, in a case that has triggered national outrage over the people trafficking business.Emergency workers discovered the bodies early on Wednesday inside the refrigerated container of a truck parked in an industrial area east of London, shortly after it had arrived on a ferry from Belgium.Police are conducting the country's largest murder probe in more than a decade into what Prime Minister Boris Johnson described as an "unimaginable tragedy".The local police force, who have arrested the truck's driver on suspicion of murder, said eight of the dead were women and 31 were men."All are believed to be Chinese nationals," Essex Police said in a statement on Thursday.However the Chinese embassy in London said on Friday that British police had yet to confirm their nationality, a day after a consular official travelled to Essex.An embassy spokesperson earlier said Chinese authorities had read the reports with a "heavy heart" and were in close contact with police "to seek clarification and confirmation".The deaths echoed the discovery of 58 Chinese immigrants hidden in a Dutch truck in the English port of Dover in 2000. Only two survived."It (has) happened elsewhere but it makes you more shocked that it could happen in your area," May Lovett, a 33-year-old owner of a cafe by the local docks, told AFP."I don't know how people can be so evil," added Rashda Imran, a mother living in the area for 18 years.In China the news had gathered more than 870 million views on China's Twitter-like Weibo platform by Friday morning, with more than 165 000 comments."No matter what nationality they are, it's a tragedy," said one.Northern Ireland connectionWith the help of immigration officials and the National Crime Agency (NCA), Essex Police are leading the biggest murder probe in Britain since the 2005 London terror attacks that killed 52 people.Its officers searched three properties in Northern Ireland overnight in connection with the investigation.The addresses are believed to be linked to the arrested truck driver, a 25-year-old man from the province, who police have remanded in custody until Friday.Police said a coroner would try to establish the cause of death of the 39 victims, before investigators then attempt to identify each individual.Belgian probeThe container section of the articulated lorry came by ferry from the Belgian port of Zeebrugge into Purfleet on the River Thames estuary - a crossing that takes nine to 12 hours.Prosecutors in Belgium have launched their own probe and confirmed on Thursday the container had on Tuesday passed through Zeebrugge, one of the world's busiest ports for cargo on trucks."It is not yet clear when the victims were placed in the container and whether this happened in Belgium," the federal prosecutor's office said. Essex Police said the tractor unit of the truck entered Britain on Sunday on a ferry from Dublin to the Welsh port of Holyhead.They had earlier said they believed the tractor unit originated in Northern Ireland.The vehicle had licence plates issued in Bulgaria after it was registered there in 2017 by an Irish citizen, according to Prime Minister Boyko Borisov.He said the unit had not entered Bulgarian territory since and there was "no connection with us".More Chinese migrants?In another incident on Wednesday, police in Kent in southeast England said they had discovered nine people stowed away inside another truck, after stopping the vehicle on a motorway. They were handed over to immigration officials.The NCA warned in its last annual report that traffickers "favour hard sided refrigerated lorries to transport migrants to the UK".It also said Belgium had become "a major focus for people smugglers" targeting Britain.Hua Po, a Beijing-based political analyst, said the flow of Chinese workers to Europe has gone up as "China's own policy has become more and more conservative and closed" under President Xi Jinping."The survival of private enterprises is becoming more and more difficult, resulting in an increase in the number of unemployed people," Po told AFP.According to the state-run Global Times on Friday, many Chinese immigrants leave via Fujian, and their destinations are usually the US, UK, Western European countries or Japan.Wang Yiwei, director of the institute international affairs at Renmin University in Beijing, told the Global Times that the "chaotic situation of Brexit" might have made the immigrants think it was a good time to try and enter Britain unnoticed.