As firecrackers erupted in the background, Sarath Fonseka promised to carry on with his challenge to the government.

 

"I will sacrifice my life to serve the people of this country. My courage will not be shattered even if they detain me for 10 years and I will not stop performing my duty," he said.

 

He was freed as a result of a pardon issued by Rajapaksa, who signed the officials papers on Saturday.

 

Fonseka's release came after Foreign Minister G.L. Peiris met with U.S. Secretary of State Hillary Clinton on Friday in Washington, with the protection of human rights highlighted in their meeting. The U.S. has called Fonseka a political prisoner.

 

Fonseka had been credited with leading Sri Lanka's army to victory in the country's long and bloody civil war against ethnic Tamil rebels. But he was jailed after challenging Rajapaksa in elections.

 

He was court-martialed on several charges related to his military service. Fonseka said the cases were a political vendetta to persecute him for daring to run against Rajapaksa. The government denied the accusation.

 

The court-martial stripped him of his title, medals, pension and other honors, dishonorably discharged him from the army and sentenced him to a 30-month jail term.

 

In November 2011, he was sentenced to an additional three-year term for allegedly implicating the defense secretary and president's brother Gotabhaya Rajapaksa in war crimes during the civil war.

 

About 3,000 supporters gathered in front of the prison in Colombo on Monday, cheering and shouting slogans. They blocked traffic on a main road for hours.

 

Fonseka vowed to continue his struggle to create "a free and fair country" and urged the people to join hands with him in his endeavor.

 

The details of Fonseka's release — including whether it restores his right to contest elections — were not immediately clear. According to Sri Lankan law, a person who has served six months or more of a prison term longer than two years cannot contest elections for seven years. A full presidential pardon could restore those rights.

 

Fonseka and Rajapaksa had a falling out months after the war ended in May 2009, and their relationship deteriorated further after Fonseka challenged the president in elections.

 

While in detention, Fonseka won a parliamentary seat on the opposition ticket in April 2010, but was disqualified from holding office after the court-martial.

 

Sri Lanka has faced growing criticism over alleged rights abuses in the final phase of the civil war. Its ties with Washington have been strained by U.S. sponsorship of a resolution passed by the UN Human Rights Council in March to press Sri Lanka to conduct an independent probe into civilian deaths in the final months of fighting.

 

More than 80,000 people were killed in the conflict, in which ethnic minority Tamils were seeking a separate state, claiming decades of discrimination by the Sinhalese majority.