The family of a 10-year-old boy who was killed by a dog in south Wales have said they are “absolutely heartbroken”, as an inquest opened into his death. Newport coroner’s court heard that the injuries Jack Lis sustained were “unsurvivable” after he was mauled while entering a friend’s house near his home in Pentwyn, Caerphilly. The provisional cause of death was given as “severe injuries to the head and neck”. Caroline Saunders, a senior coroner in Gwent, said the circumstances surrounding Jack’s death were “violent and unnatural”. She adjourned the inquest for further inquiries to be made. Gwent police said on Friday that a 28-year-old woman from Caerphilly had been released on bail after being arrested on suspicion of being in charge of a dog dangerously out of control. The force said two men from the Caerphilly area had been released after voluntarily speaking to police over being in charge of a dog dangerously out of control. A statement from Jack’s family said: “We are absolutely heartbroken. Our lives will never be the same without Jack. This is not something any parent should ever have to be writing. “Our boy made us the proudest parents and family on the planet. He was the sweetest of boys. He’s for ever in our hearts. Sweet dreams, Jack, our perfect boy.” On Monday afternoon police were called to a property in Pentwyn after reports of a dog attack. Officers attended, including specially trained firearms officers, alongside paramedics from the Welsh ambulance service, who were unable to save Jack. Jack and his friend were alone when the attack happened. The friend sought the help of a neighbour who lived on the same street but the man was unable to stop the dog. The animal was shot by the firearms officers. Ch Supt Mark Hobrough said: “The work to identify the breed of dog involved this attack continues. Once this is completed, we will be able to establish if the breed features on the list of illegal dogs to own in this country. Any other criminal offences identified will be investigated fully by officers.” He appealed to the public not to name on social media those suspected of being involved. He said: “It is vital that people are considering the tone and language used in comments posted on social media about the identities of anyone involved in this matter as part of our inquiries. “It is important that people think about how their social media comments or posts could impact the ongoing investigation and Jack’s grieving family.” Hobrough said his condolences and thoughts were with Jack’s family and friends as well as anyone else affected by the incident.