The bus was travelling from Kashmere Gate in Delhi to Greater Noida and there were nearly 40 passengers on board, said a police official.
The accused passengers boarded the bus at Atta. When the bus reached the expressway and conductor Narinder Kumar asked the men to buy tickets. On this, they assaulted the conductor. When bus driver Rakesh came to Kumar's rescue, the accused assaulted him also, he said.
They then snatched the cash bag and ran away. The ticket machine of the bus also got damaged in the melee.