A five-year-old boy in hospital with serious injuries is thought to have been shot by an eight-year-old boy, police have said.

The injured child is being treated at the Royal London hospital following the incident in Wickford, Essex, on Sunday.

An 18-year-old man was arrested on suspicion of possessing a firearm and drug offences and has been released on police bail until 6 January.

The weapon, said by police to be illegally held, and other legally-held firearms at the property were handed over to officers, the force said.

Police said they were speaking to members of the family to determine the exact circumstances leading up to the incident but believed it was an accidental discharge of the weapon and inquiries were ongoing.

A spokesman said that although the incident is said to have involved relatives, "we don't at this stage know the exact relationship".