Colombo, May 2 (IANS): Sri Lanka's main opposition party has called for the immediate release of the jailed Sarath Fonseka, who led the army when it crushed the Tamil Tigers in 2009.

Fonseka, who challenged Rajapaksa in the 2010 presidential election, was sentenced to an additional three years in prison after his sentence expired in January this year.

At a May Day rally here, United National Party's (UNP) deputy leader Sajith Premadasa called for the "unconditional release" of Fonseka, who has filed an appeal for bail.

Besides, the country's main Tamil party - Tamil National Alliance - reiterated its demand for a political solution to the ethnic conflict by devolving power through devolution.

At a separate rally, President Mahinda Rajapaksa said that "international conspiracies" under the guise of probing human rights would not be allowed to break Sri Lankan's unity.

The unity of working people is essential to rebuild this nation," he said Tuesday.

"I am confident you will not deviate from this task. I promise that no outside influences will derail the intentions of this government with talk over human rights," Xinhua quoted the president as saying.

Sri Lanka has come under widespread attack over human rights abuses in the war that crushed the Liberation Tigers of Tamil Eelam (LTTE). Colombo has denied the accusations.