Thousands of people demonstrated in Bahrain on Friday to denounce a proposed closer union with neighbouring Saudi Arabia, dpa reported.
Many believe that such move is designed to crush a pro-reform movement led by the Shiite majority in Bahrain, which is ruled by a Sunni monarchy allied with Saudi Arabia.
Reports of the plan surfaced earlier this month and were rumoured to be inked at a summit of the leaders of the six-nation Gulf Cooperation Council (GCC) held in the Saudi capital Riyadh last week.
However, the summit ended without formal steps to implement the union plan, which is believed to be a prelude to a larger union between the GCC countries.
The bloc comprises Bahrain, Kuwait, Oman, Qatar, Saudi Arabia and the United Arab Emirates.
The protesters, responding to a call by major opposition groups, rallied along the Budaiya highway, north of the Bahraini capital Manama.
Sheikh Isa Qassim, a leading Shiite clergyman, criticized the unity plan, saying it is aimed at limiting freedoms.
"It is clear that the proposed unity is not meant to unify the people of the region," he said in a Friday sermon in Duraz village, north of Manama.
"The people are neither a herd of sheep nor children to give up their freedoms," he added.
Thousands of Iranians on Friday attended rallies reportedly organized by the government to protest against what Iran says is Saudi meddling in Bahrain's affair.
The Iranian parliament on Monday condemned the plan and urged Bahrain, a small Gulf country, to concentrate on realizing the "legitimate demands" of its opposition.
Several Sunni Arab countries have accused Shiite-dominated Iran of standing behind the unrest in Bahrain.
Saudi Arabi and the United Arab Emirates last year send troops to Bahrain to help squash anti-government protests inspired by the Arab Spring uprisings.