A suicide bomber blew himself up on Tuesday at a security post in a tribal region bordering Afghanistan while one of his accomplices was killed in firing by the troops.No one was injured in the suicide attack on the Frontier Constabulary post at Kapakh Kandao in Mohmand Agency, the army said in a statement. Three militants approached the post at 10.30 am local time. When the troops challenged the militants, the suicide bomber blew himself up while one of his accomplices was killed in retaliatory firing.