The mishap occurred on National Highway-8 under Mangaliawas Police Station when the victims were on their way to a railway station, police said.
Miraj Alam (21), S N Chaudhary (35), Pintu (25) and Prakash Sindhi (32) died on the spot while five injured were admitted to JLN Government Hospital in Ajmer and their condition is stated to be stable.
They all were the labourers working in a cement factory, police added.