Police administration on Sunday has revealed the cause of the explosion in Kamakhya- Dekargaon intercity express took place near Harisinga railway station under Udalguri district on Saturday night.

Deepak Kumar, IPS. IGP(L&O),Assam has told to media that "Preliminary investigation reveals that a Hand made Grenade exploded resulting in the blast in Kamakhya- Dekargaon intercity express on Saturday. Further details are being ascertained."

Meanwhile, the United Liberation Front of Asom (Independent) (Ulfa-I) has denied its involvement in the grenade explosion.

A spate of terrorism activities over the last few days has put a question mark over tall claims of the state government with regards to improving law and order machinery.