The home secretaries, Omar Farooq of Bangladesh and Dhirendra Singh of India, led their respective delegations in discussing a range of issues centering on security along the 4,156-kilometre border shared by the two neighbours.Joint security operations on the border, implementation of border treaties, and insurgency and terrorism issues dominated the opening day of the fifth Dhaka-Delhi home secretary-level biennial talks that began in the city yesterday after four years.