The four miscreants looted cash and valuables from the house of Dr Dilip Chaurasia in George Town police station area of Allahabad last night, Home Department said.
One of the robbers was nabbed by the locals and handed over to police, they said.
On the information of the arrested person, police today searched the room of his associates and recovered eight pipe bombs, detonators, finished and semi finished bombs, electronic devices, batteries, tool kit among other things, they said.