The accused who were hiding in a house on the city outskirts were nabbed yesterday by a special police team, police said.
The accused have been arrested as Santhosh (25) and Pattabi (26).
The duo were among four who had managed to escape from the hospital hours after the explosion that occurred in a residential area on May three.
Police said search is on for the another accused, who is still at large.
Santhosh is a rowdy sheeter of Sirkazhi in Nagapattinam district.
Barring Mohan Ram, also an history sheeter, four others gave a slip to police and escaped from the hospital.