London - Thirty-one people, including several children, were discovered in poor health, packed inside a shipping container being unloaded at a dock in eastern England on Saturday morning, police said. One man has died and the others were being treated by ambulance crews at the scene and in hospitals, they added in a statement. The container was being unloaded at Tilbury docks in Essex from a ship that had arrived from Zeebrugge, Belgium. Tilbury, on the River Thames, is primarily a bulk cargo and container port and not such a prime target for illegal immigrants as those on the south coast, such as Dover.Essex police said they had started an investigation and were working with immigration and health authorities. No further details were immediately available. The men, women and children, all believed to be from the Indian subcontinent, were discovered inside the container at Tilbury Docks, east of London, on a ship that came from the Belgian port of Zeebrugge. All the survivors were taken to nearby hospitals; two were in a serious but not life-threatening condition, while the others were suffering from dehydration and hypothermia.Cases of immigrants trying to enter Britain illegally, often in dangerous circumstances, are not rare. The local police have vowed to bring to justice anyone involved in putting the people in the container, while the local lawmaker said the authorities needed to understand what was motivating people to go to such lengths to reach Britain. Because a body was found, Essex Police has launched a homicide investigation.Of 64 containers aboard the P and O ship that arrived early Saturday, police have opened 30 so far to check for any other people. ‘Staff here at the port became aware of screaming and banging coming from a container,’ police superintendent Trevor Roe told reporters. ‘As a result of that noise, staff were alerted and immediately breached the container to find 35 persons within that unit.‘We believe them to come from the Indian subcontinent.’ P and O Ferries said the container arrived on the quay in Zeebrugge around an hour before it was loaded onto the ferry. Two hours later, the ship began the eight-hour overnight crossing. The people were discovered on the ship's arrival in Tilbury.The firm's Natalie Hardy said the commercial ferry was carrying 64 containers, 72 trailers and five trucks and drivers. The dead man was pronounced deceased at the scene by emergency medics in Tilbury. ‘It is a homicide investigation from the police point of view,’ Roe said, though there was no suggestion anyone inside the container was a suspect. He added: ‘This is a humanitarian issue, and the welfare of these patients is a priority.’Officials have faced a language barrier in their efforts to communicate with the survivors. Roe said once the survivors are fit and well they will be formally interviewed through interpreters. He said the police investigation would look into ‘the gangs or whoever may be involved in this conspiracy to bring these people in this way over to this country. ‘Clearly we need to try to bring them to justice.’Stephen Metcalfe, the local member of parliament, said the incident was ‘tragic’. ‘The fact that so many people appear to have travelled so far and are so desperate to get into the UK - either on their own or being trafficked - is really very sad,’ he told the BBC. He said it was important ‘to get to the root causes of what is motivating people to go to such extreme lengths to travel from other parts of the world to get into the UK’ and combat people-trafficking.The BBC quoted the UK Border Force as saying that in 2012-13, more than 11,000 attempts to cross the English Channel illegally were prevented at ‘juxtaposed controls’. In 2000, 58 Chinese illegal immigrants suffocated to death after the air vent to their sealed container on a truck was closed on their way to the southern English port of Dover. In July last year, British police arrested two people after 15 asylum seekers were found hidden in a tanker on board a ferry at Dover. Earlier this month, 16 men, all thought to be from Ethiopia, were found in a refrigerated unit in a truck outside London. They were arrested on suspicion of entering the country illegally. And in June, eight suspected illegal immigrants, all Afghan nationals, were rescued from the English Channel when their small boat lost power.