It was not said what these measures would be, but rather that senior police officials would make any such decisions.
The government has placed blame for the attack, which took place about 160km south of Colombo, the capital, on the separatist Liberation Tigers of Tamil Eelam (LTTE).
It comes as the LTTE battles for survival against government forces, who have pushed the group back into a small jungle area of the island's northeast.
No one has yet claimed responsibility for the attack.
The explosion, which injured at least 35 other people, was said to have targeted six government ministers as they led a religious procession.
One minister, Mahinda Wijesekera, the communications minister, was critically injured and remains on life support.
Wijesekera suffered head injuries in the explosion and was airlifted to Colombo where he received four hours of surgery.
If the LTTE carried out the attack, it would convey the group's continued ability to strike far from its strongholds in the north east, even as the government claims increasing military success.
However, Palitha Kohona, the foreign affairs ministry secretary, told Al Jazeera that the LTTE will eventually be defeated as a guerrilla force.
"There's very little doubt that it is the Tigers that are doing it. Because the attack bares all the hallmarks of a Tiger suicide bombing," he said.
"There was a time when we were told ... that we could not defeat them militarily. We have done that.
"We are now being told that we can't defeat them as a guerrilla force. We will do it."
The LTTE has been fighting a secessionist war for an independent homeland in the northeast for the country's Tamil minority since 1983.