The deceased is Mukul Munshi, 40, son of late Yusuf Munshi and a member of inter-district robber gang.
He is an accused in six cases including robbery filed with different police stations in Kushtia.
Kuhstia RAB 12 Unit Commander Major Mossaddek Ibne Mujib said: “Acting on a tip-off, we raided the area around 3am on Sunday.”
He said a group of seven to eight robbers while preparing for a robbery in the area.
“Sensing our presence, the robbers opened fire at us,” the commander said.
In retaliation, RAB officials fired back that left one of them dead on the spot while the others managed to flee the scene.
Two RAB officials were also injured in the incident.
Meanwhile, a foreign-made pistol, a magazine, two rounds of bullets, two machetes and rope were recovered from the spot.
The body has been sent to Kushtia General Hospital morgue.