The report cited exclusion of the foreign media, harassment of human rights defenders, arrests of bloggers and Internet activists, prosecutions and defamation campaigns against free expression activists, and disruption of communications after mass protests first erupted in February 2011.

It said Bahrain, where the Wahhabi Al Khalifa family rules a majority Shi'ite population, slowed down the Internet and increased filtering during the uprising, which was put down by force after one month in March 2011. Bahrain, a U.S. ally that hosts Washington's Fifth Fleet, fell in RSF's press freedom index to number 173, seven places from the worst offender, Eritrea, the watchdog said.

In its response, the Bahrain government said it was in the process of improving media standards, according to the recommendations of a commission of international legal experts which criticised media policy in a hard-hitting report in November.

A statement faulted the group for not citing Bahrain's move to establish the commission, the Bahrain Independent Commission of Inquiry (BICI).

"The government of Bahrain remains committed to meeting international media regulation standards and is working hard to improve its domestic media environment. Nevertheless, reform is a process and not an event," the government's Information Affairs Authority (IAA) said.

"We hope that Reporters Without Borders follows this process closely and engages with us to ensure future reports reflect an accurate picture of the media environment in Bahrain."

The BICI report recommended that Bahrain's government allow opposition groups access to state media.

However, state television has not covered a number of recent large-scale rallies and marches with interior ministry approval, including a rally last Friday that was the biggest since the unrest began.

Major pan-Arab media outlets controlled by fellow Persian Gulf states also offer scant coverage of these events.

Friday's protest saw about 500 thousands of Bahrainis take to the streets to demand democratic reforms, stepping up pressure on the government.

Shi'ites complain of political and economic marginalisation, charges the government rejects. It has allowed the elected parliament more powers of scrutiny over ministers and budgets. But the opposition want a move towards full democracy, giving parliament full powers to legislate and form governments.