The experts and senior government officials told Maan news agency the Palestinian Authority instructed Internet providers to block access to as many as eight news outlets.
A detailed technical analysis indicated technicians at the Palestinian Telecommunications Company tweaked an open source software called Squid to return error pages for the targeted news sites, the security experts said.
Many of the blocked sites were described as loyal to former Fatah leader and Abbas critic Muhammad Dahlen.
An official with first-hand knowledge of the move said the order to block came from Ahmad al-Mughni, the Palestinian attorney general, acting on instructions from higher up in the government.
Danny O'Brien of the U.S. press freedom group Committee to Protect Journalists, said asking Internet service providers to block a few Web sites is usually how a government censorship program begins.