MANAMA (Reuters) - Thousands of mostly Shi'ite Muslim Bahrainis protested on Wednesday against giving citizenship to Sunni foreigners serving in the military, whose troops have killed seven in the worst unrest since the 1990s.
Bahrain, home to the U.S. Navy's Fifth Fleet, has seen weeks of protests by its disgruntled Shi'ite majority, which says it is discriminated against by the Sunni al-Khalifa ruling family.
No stranger to sporadic protests and rioting, Bahrain has been gripped by the worst unrest since the 1990s after a youth movement took to the streets last month, emboldened by revolutions that toppled the leaders of Tunisia and Egypt.
Protests have been peaceful after initial clashes but many of the protesters still occupying Manama's Pearl Square are demanding the al-Khalifa family be ousted.
The bigger and more moderate Shi'ite opposition group Wefaq only demands a new government and a new constitution under which the government would be elected.
A thorny issue for all opposition groups has been Bahrain's practice of giving citizenship to Sunni foreigners serving in the kingdom's armed forces, which they see as an attempt to alter the country's sectarian balance.
The protesters marched by the immigration authority in Manama, chanting anti-government slogans and holding up signs that read "Stop naturalization!"
"All those that are naturalized will be pro-government, and those in the police and army will follow their orders even if they are against the Bahraini people," said protester Khaled Ali.
Only half of Bahrain's population of about 1.2 million are native Bahrainis. Protesters said they only oppose settling those foreigners who are recruited to serve in the armed forces.
The opposition also complains that families of naturalized Sunnis have better access to government services such as housing, education and health.
"We want them out because they're sharing the services with original Bahrainis. We have to wait 15 years for (government) housing, and they get it immediately after arriving," said Ali.
Opposition activists estimate that up to half of Bahrain's approximately 20,000-strong national security apparatus could be made up of Sunnis from Pakistan, Jordan and Yemen.
The interior ministry said this week it plans to create 20,000 jobs and said they would be open to Shi'ites.
The government says there is no plan to change the country's sectarian balance and that all naturalization is done with full transparency and in accordance with Bahrain's immigration policies.
Bahrain's king said in December the government would start limiting the practice, in what observers said was a gesture to the opposition over a contentious issue.
"He said that, but what's going on under the table is different," said protester Taha Alderazi.
Bahrain saw the first clashes between Sunni and Shi'ite residents last week when at least a hundred residents attacked each other with metal sticks and batons in Hamad Town, an area where both sects live, including settled Sunnis.
It was not clear what prompted the clashes that lasted about two hours before police and politicians calmed the situation, but residents said that Syrians settled in Bahrain had been involved.
Reporting by Frederik Richter and Lin Noueihed; Editing by Sonya Hepinstall