Two men have died following the crash involving a double decker bus and a lorry on the A47 in Wisbech, Cambridgeshire Police said.
The bus driver was one of the two men killed in the crash, First Eastern Counties bus company said.
Managing director Steve Wickers said: “As confirmed earlier today, one of our buses was involved in a fatal road traffic incident with a lorry on the A47 in Guyhirn.
“Two people have lost their lives in this incident, one being a driver based in our Kings Lynn depot. I am shocked and saddened by what has happened.
“Our thoughts are with the families of the deceased and we will be providing as much support to them as we can through this difficult time.”
Seven others have been seriously injured and 11 people have minor injuries,Cambridgeshire police spokesman said.
Around a three-mile stretch of the A47 remains closed following the collision on Tuesday morning.
Footage from the scene shows the bus, which had been travelling eastbound on the road, lodged into the side of the lorry, which appears to have been heading westbound.
The crash, involving a Bretts Transport lorry, happened near the firm’s distribution centre at Thorney Road in Guyhirn.
A spokesman for Bretts said: “We acknowledge there has been an incident on the A47 this morning involving one of our vehicles just outside our premises.
“At this stage we are giving the emergency services our full support and co-operation.”
According to its website, the firm specialises in deliveries to the retail, food service and food manufacturing sectors, delivering more than 4,000 tons of canned food and other grocery products along with 5,000 pallets of food grade packaging each week.
The injured have been taken to Peterborough City Hospital and the Queen Elizabeth Hospital in King’s Lynn.
East of England Ambulance Service said it had sent seven ambulance crews, three ambulance officers, two rapid response vehicles, and a hazardous area response team to the scene.