Police respond to reports of a domestic-related incident at a property on Sterncourt Road in Bristol shortly before a grenade explosion is heard at about 6:30am. According to initial reporting cited by outlets, the explosion occurs at the address after officers are called to the location moments earlier. The same reports state that a man dies as a result of the explosion and that his ex-partner is also killed, while three other people are injured, including a child. Authorities are treating the incident as serious and are investigating the circumstances leading up to the blast, including the relationship between those involved and how the grenade came to be used. Emergency services attend the scene and local areas are affected as police carry out their enquiries. Additional details such as the exact cause of death for each person and the broader investigation outcomes are not described in the provided accounts. The matter is ongoing and police continue to piece together what happened before and during the explosion.