According to top police sources, Karnataka Police were assisted by their Tamil Nadu counterparts in a late night operation, in which two persons -- Peer Mohideen and Basheer hailing from Tirunelveli were arrested from a lodge here.
The third person was arrested from Madurai, they said, adding the trio facilitated the blast while the main culprits were still at large.
Four men were recently detained in Kerala for their alleged involvement in the case.
The arrested are being taken to Bangalore for further investigation, sources said.
The Karnataka government had announced a reward of Rs five lakh to those who provide information on the culprits responsible for the April 17 blast.