Assam serial blast

Continued with ahmedabad ,andra and delhi yesterday blast in assam.The government do know who is behind the blast they suspecting bangladesh terrosist and ulfa had joined hands and had made this serial attacking on the capital.With this blast all the indians are get tensed and security purposes are increased in all the metropolitan cities.The terrorists doing such rubbish things in india the stupids if they have guts get directly with military and fight.Why they attacking unknown people?