India on Saturday said it has a fair amount of intelligence about Pakistan's involvement in the Monday's suicide attack on its embassy in Kabul.

"We not only suspect but we have a fair amount of intelligence (on the involvement of Pakistan)," National Security Advisor M K Narayanan told Times Now news channel when asked whether India suspects Pakistan's involvement in the attack.

"The people of this country deserve to know the facts rather than being carried away by people who make statements that these are insinuations. There are no insinuations," he said.

Four Indians, including an IFS officer and a Brigadier of the Indian Army, were killed in the blast caused by a suicide bomber driving an explosive-laden Toyota Corolla.

The NSA said there was a need to retaliate to such acts of terror. "I think we need to pay back in the same coin. We are quite clear in our mind," he said.

When asked who should be paid back, he replied, "Those who are responsible."

Narayanan said India-Pakistan relations were sought to be improved through a comprehensive dialogue mechanism.

"The anti-terror mechanism was one piece of this picture. The hope was that in course of time both sides would share whatever information they have and come up with a holistic idea of what was going on," he said.

"Talk-talk is better than fight-fight. But it hasn't worked so far. In some way, we haven't arrived at the decision that we should go for fight-fight so let talk-talk continue for the moment," Narayanan said.