The area has been cordoned off and investigations are on with the help of experts. Last month a powerful 'pipe bomb' was recovered near a compound wall of a private wholesale market at nearby Uthangudi. Later it was defused. Madurai, March 14: A low-intensity bomb exploded in front of a mosque at Nelpettai here today. No casualty was reported, police said, adding a two wheeler parked there was damaged in the explosion.