"I strongly condemn this attack and I demand that there should be a thorough investigation by the NIA into the case," he told PTI.
Bhattacharya, also a senior Congress leader from West Bengal, said the Centre should be more alert about the terror activities in the country.
"The government should be more cautious and alert in dealing with terror activities," he said.
In the deadliest attack on security forces in three years, eight CRPF personnel were killed and 21 others critically wounded when terrorists rained bullets on a bus carrying them in South Kashmir's Pulwama district today.