Seven people, including a six-year-old boy and his 16-year-old sister, were killed when a bus overturned east of Vicksburg, Mississippi, Warren County Coroner Doug Huskey has said.

They were identified by their mother. Authorities were working to identify the other victims, Huskey said. The Mississippi Highway Patrol said the incident took place in the early hours of Saturday on Interstate 20 near Bovina in Warren County when a 2018 Volvo commercial passenger bus travelling westbound left the roadway and overturned.

Thirty-seven passengers were transported to different hospitals with unknown injuries, the agency said. It said the co-driver was not transported.

"Anytime you have people injured or killed, it’s tragic but when you have a situation like this where you have multiple fatalities and multiple injuries, it makes it even worse,” Warren County Sheriff Martin Pace told an ABC affiliate.

Huskey said most of the passengers on the bus were Latin American. (Agencies)