Heavily armed Maoists carried out a deadly ambush on a key national highway in Bastar district early on Saturday in which an Assistant Platoon Commandant (APC) of Special Task Force (STF) was martyred, a senior police officer said.The attack took place at around 2 am when a contingent of STF was on operational task on the national highway (NH) 30 in Darbha region after reports that guerrillas had blocked the highway which connects Bastar region’s key town Jagdalpur to Sukma district. “It was a well-planned deadly ambush which trapped a bigger STF contingent, the cops displayed bravery and effectively countered Maoists in which STF’s APC Krishna Pal Singh was killed while a constable Santosh Yadav sustained injuries,’’ Inspector General of Police (SIB) Deepanshu Kabra told The Pioneer.