Sulfikar Ali, 22, and Shabeer, 24, were arrested from the house of Shabeer's relative at Kecheri near Kunnamkulam in the district yesterday, they said.
The arrest was made by a police team from Karnataka and Tamil Nadu after following the duo's mobile phone signals, they said.
With this the total number of arrests in connection with the blast, that left 17 persons injured, including 11 policemen, has risen to 13.