Liberation Tigers of Tamil Eelam suicide squads have infiltrated Colombo to kill Sri Lankan President Chandrika Kumaratunga, presidential spokesman Harin Peiris said on Wednesday.
Peiris also said Kumaratunga would break up the island's embattled northeastern province, a move that will take away a key concession to the rebels.
"They (rebels) have carried out surveillance and we have very credible information that they are now planning to assassinate the president," Peiris said.
He said the Muslims in the multiethnic eastern region did not want to be dominated by the Tamil-majority north.
The two regions, which together account for about a third of the island's landmass, were united into a single entity in 1987 under the Indo-Sri Lanka peace accord as a concession to Tamils.
Although the accord was not fully implemented, the merger remains in force.
Peiris declined to say when and how Kumaratunga would carry out the de-merger of the northeastern province.
The remarks came as the Tiger rebels prepared to hold a key meeting in Paris to formulate a response to the government's latest offer of an interim administration in the island's northeast.
