A top government official says that Sri Lanka's president has dissolved the country's parliament.

The official said the order from President Mahinda Rajapaksa has been sent to the government printers, and this will set the stage for new general elections. He spoke on condition of anonymity in line with government policy.

The decision comes a day after the military arrested Rajapaksa's main challenger in the country's presidential poll, held last month.

Rajapaksa won that election by a landslide, according to official results. The opposition has refused to accept the defeat of their candidate, former army chief Sarath Fonseka.

On Tuesday, the opposition called for countrywide protest after Fonseka was arrested Monday.