They had returned in a police van at about 7.30pm on Wednesday.
As per preliminary inquiry, there could have been a lapse in their security check as all three probably carried sharp edged blades with which they cut the bathroom grills and managed to escape around 2.30am with the help of their accomplices waiting outside the jail, Kumar said.
They scaled the wall with the help of a rope.
He said while three inmates managed to escape in the dark of the night, two others were nabbed when security personnel opened fire. Efforts were on to trace them.