At least 50 people of a civil society group close to the Maoists were arrested for staging a protest against the President's decision to reinstate Army Chief.
Shyam Shrestha, Krishna Pahadi and Devendra Raj Pandey were among the civil society leaders who were arrested from the Sheetal Niwas area, which is declared as a prohibited zone.
Some four dozen people including civil society activists and Maoist cadres were arrested from the area.
There was heavy deployment of riot policemen to avert clashes in the wake of latest political developments.
The leaders were opposing the President's decision to reinstate Army Chief Rukmangad Katawal. They claimed that the President's move was unconstitutional and he should withdraw the move.
Meanwhile, Maoists have decided to block the Parliament session soon after quitting the government.
The Maoists' secretariat meeting held on Tuesday decided to obstruct the Parliament Session until the President withdraws his decision to reinstate the Army Chief.