"I don't know whether it is big or small. It is serious," National Security Advisor Ajit Doval told reporters here after a high-level meeting which took stock of the situation in the country.
He was replying to a question on whether the Gurdaspur incident was a big terror attack.
The meeting, chaired by Home Minister Rajnath Singh, directed the BSF to remain in high alert and find out how the three terrorists could breach the IB and entered India from Pakistan.
The high-level meeting was attended by Defence Minister Manohar Parrikar, Doval, Union Home Secretary L C Goyal, BSF Director General D K Pathak and top officials of para-military forces and intelligence agencies.
After the meeting, an official spokesperson said the Home Minister appreciated the operation of the Punjab government and various measures were discussed to prevent recurrence of such incidents in the future.