"The Maoist politburo meeting held recently in an undisclosed location has decided not to destroy physical infrastructures nor to indulge in political killings," said a statement by Maoist chairman Pushpa Kamal Dahal, alias Prachanda, late on Tuesday.
Maoist sources said the decision was taken to garner support from the public who had been dismayed at a surge in violence since the rebels pulled out of a ceasefire two months ago. About 211 people had been reported killed since 27 August.
The statement said the rebels would not attack any Nepalese or international non-governmental organisation or their projects, except "ones run directly by the United States."
The rebels are staunchly anti-American, had targeted US interests and during the failed peace process this year demanded the Nepalese government should renounce US military aid.
The party said it would avoid destruction of village development committee (VDC) buildings and communication towers and vacant army barracks and police posts.
Since the end of the seven-month ceasefire, the guerrillas had attacked several empty army and police posts and burned and bombed VDC buildings.
About 2,000 VDC buildings and dozens of telephone towers had been destroyed by the Maoists in the last two years, according to the Nepal Telecommunications Authority.
The rebels also said they would not carry out attacks against lower level unarmed police and army personnel while on leave or their families.
This major shift of policy came in the Maoist camp 55 days after they unilaterally ended the ceasefire and backed away from the third round of peace dialogues and resumed armed conflict.