The Nepalese authorities arrested scores of activists, cut phone services and ordered a daylight curfew for Friday when opposition parties planned to demonstrate in capital in defiance of ban on marches.
"We call on the Nepalese authorities to release Shyam Shrestha and any other journalists they have detained immediately." said Ann Cooper, CPJ's executive director. "Restrictions on the press are often an indication of a broader crackdown."
Nepalese journalists report that those detained in the early morning raids are being held in at least four sites in and around Kathmandu. Others are under house arrest. The Associated Press quoted an official as saying authorities planned to arrest up to 200 people.
The press has been under attack from the government since King Gyanendra seized absolute power in a coup on February 1, 2005.