Kushinagar (Uttar Pradesh), Nov 13 (IANS): Four persons, including a cleric, have been arrested in connection with a blast at a mosque here.

The police had registered an FIR against seven persons. Among the four arrested is the 'imam' of the mosque, Maulana Azmuddin, while three others are absconding.

The motive behind Monday's blast is not known yet.

Forensic reports have now confirmed that the explosion was caused by explosives stored in the mosque. Initially, it was believed that the blast was caused by an explosion in an inverter battery.

ATS Gorakhpur, intelligence agencies and Local Intelligence Unit (LIU) teams have joined the probe.

The blast took place in Bairagai Patti village here on Monday afternoon. The explosion was strong enough to rip apart doors and windows in the mosque, say reports.

During interrogation, the cleric admitted that he and some other youths had kept the explosives in the mosque.

The others arrested are Izhar, Aashiq and Javed -- all residents of the Bairagi Patti village, said Vinod Kumar Mishra, SP (Kushinagar).