The identities of the deceased could not be immediately known.
Talha Bin Zashim, station officer of the Department of Fire Service and Civil Defence, said that the Chattogram-bound lorry turned upside down before smashing the Dhaka-bound private car at an under-construction U-loop area on the highway around 12:44pm.
The accident left four people dead on the spot, he said, adding that the deceased were passengers of the private car, reports UNB.
Two firefighting units from Chouyabazar fire station rushed to the spot for carrying out the rescue operation, he said.