Noore Alam confessed the rape to the court after his arrest
The bus was being repaired when it was hit by the van early on Saturday at Mirsarai, said Highway police inspector Md Fariduddin.
He said the five killed, including women, were between 25 and 50 years of age, he said.
Four of them have been identified as Syedur Rahman, 50, Mizanur Rahman, 35, Shahida Aktar, 25, and 'Susmit,' 21.
Inspector Fariduddin told bdnews24.com that a bus, heading to Chittagong from Dhaka, was being repaired after its engine malfunctioned.
"The covered van, also heading in the same direction, hit the stationary bus, before killing five people on the spot," he said.