The boys escaped drowning by climbing atop a concrete platform built by the Chandrapura Thermal Power Station yesterday.
The incident at Pachaura village came close on the heels of the tragedy in Himachal Pradesh in which 25 engineering students from Hyderabad and a tour leader were washed away in the river when Larji hydropower project authorities suddenly released water from the barrage.
Bokaro Deputy Commissioner Uma Shankar Singh said, "The incident occurred when all the boys in the age group of 15/16 went to the river for fishing yesterday afternoon.
"As the water swelled following opening of one sluice gate at the Tenughat Dam in Bokaro district, they climbed atop a concrete platform built by the Chandrapura Thermal Power Station yesterday."
The boys, who were residents of nearby villages, were rescued by police last night at around 11.30 PM, he said.