Ten security personnel were killed and as many injured in a landmine explosion triggered by Maoists in Orissa's Koraput district on Sunday.<br/><br/>According to police the landmine exploded at Tanginiguda when a van carrying jawans of the elite anti-naxalite Special Operation Group was returning from an operation from adjacent Malkangiri district. <br/><br/>The injured have been admitted to nearby hospitals. Additional force and medical team have been sent to the spot. Sources said a brief exchange of fire also took place between the security personnel and the rebels near the blast site and details were awaited.