Sri Lanka was on Tuesday plunged into a political crisis with President Chandrika Kumaratunga sacking three senior ministers and suspending parliament in a major showdown with her arch rival, Prime Minister Ranil Wickremasinghe, who is in Washington for talks with US President George W Bush.

Also Read LTTE is ready with power-sharing plan India can have a role in Lanka, says US

Kumaratunga, who has wide executive powers and has been at loggerheads with the prime minister over the peace process, had earlier dismissed Defence Minister Tilak Marapana, Interior Minister John Amaratunga and Information Minister Imthiaz Bakeer Markar. She also removed the bureaucrats responsible for the day-to-day running of the three ministries and deployed troops to key buildings in Colombo.

The president's action, which came four days after the Liberation Tigers of Tamil Eelam submitted a power sharing proposal to resolve the country's ethnic conflict, is seen as a blow to Wickremesinghe's efforts to bring the peace process back on track.

Kumaratunga's Sri Lankan Freedom Party, which is in opposition, has expressed concern about the LTTE's proposal for a self-governing authority in the northeast of the country.

There was no immediate statement from Kumaratunga or her office on the reasons for the sudden dismissal.