The release follows a government announcement a day earlier that anyone jailed under a tough anti-terrorism law imposed by the previous government of King Gyanendra would be freed.
The remaining jailed rebels would also be freed once certain legal technicalities are completed, he said. Courts must issue individual orders for the release of each rebel. Some 160 rebels remain in jail, the AP reports.
The new government reached a cease-fire with the rebel leaders, began peace talks last month and freed hundreds of Maoists and supporters who had been held on lesser charges. But many remained in jail on charges including murder, kidnappings and crimes against the state under the anti-terrorism laws.