Forces from neighboring Gulf Arab countries will help maintain order in Bahrain, Arabiya TV reported on Monday, and an adviser to Bahrain's royal court said their forces were already on the strategic island.
"Forces from the Gulf Cooperation Council have arrived in Bahrain to maintain order and security," Nabeel al-Hamer, a former information minister and adviser to the royal court, said on his Twitter feed.
Gulf Daily News, a newspaper close to Bahrain's powerful prime minister, reported on Monday that forces from the GCC, a six-member regional bloc, would protect strategic facilities.
“The security and stability of the Gulf Cooperation Council (GCC) is a common responsibility, and this was reconfirmed by the GCC foreign ministers at their latest meeting,” a statement carried by Bahrain News Agency said.
The military force will help Bahraini authorities deal with the month-long unrest in the country.
Meanwhile, Bahrain state TV said a three-month state of emergency has been declared to try to quell political unrest threatening the monarchy.
The statement from Bahrain's king said that the nation's armed forces chief is authorized to take all measures to stamp out protests that have gripped the island nation for the past month.
Also, a top Bahraini official described Iran's criticism of Gulf forces being sent to the monarchy to help put down protests as "blatant interference" in its affairs, state news agency BNA said Tuesday.
1,000 troops from Saudi
Television footage showed convoys of unmarked, desert-brown armored vehicles crossing from Saudi's Eastern Province into Bahrain, the home of the U.S. Fifth Fleet.
The Saudi government said it had responded to a call for help from its neighbor as Saudi-led forces from the Gulf countries' joint Peninsula Shield Force crossed the causeway into Bahrain.
"The council of ministers has confirmed that it has answered a request by Bahrain for support," the Saudi government said in a statement carried by the SPA state news agency.
A Saudi official said earlier that more than 1,000 Saudi troops, part of the Gulf countries' Peninsula Shield Force, have entered Bahrain where anti-regime protests have raged for a month.
The troops entered the strategic Gulf kingdom on Sunday, the official told AFP, requesting anonymity.
According to a Saudi security official, one Saudi soldier was shot dead by opposition protester in Bahrain.
Meanwhile, thousands of Bahraini protesters marched from the Pearl Square roundabout toward the Saudi embassy on Tuesday, in protest against the Saudi-led Gulf Arab troops entering the country.
500 policemen from UAE
Under an agreement of the six-country Gulf Cooperation Council (GCC), "any harm done to the security of a member state is considered a harm done to the security of all members," it said.
Foreign Minister Sheikh Abdullah Bin Zayed Al Nahyan said the UAE has sent around 500 policemen to Bahrain.
“The Bahrain government asked us to look at ways to help them to defuse tension in Bahrain,” he told journalists when asked about the UAE decision to send security forces into the kingdom at a gathering of Group of Eight foreign ministers in Paris. He later went into talks with U.S. Secretary of State Hillary Clinton.
Earlier, UAE's official news agency WAM said the UAE is sending a force to Bahrain as part of the Peninsula Shield. Dr Anwar Mohammed Gargash, Minister of State for Foreign Affairs, said the move reflects the UAE’s commitment towards its brethren within the framework of the GCC bloc.
“The security and stability in the region requires all of us to stand united in one rank so as to safeguard our national gains and prevent any strife for a better future,” Gargash said.
Iranian Foreign Minister Ali Akbar Salehi responded to GCC's move by demanding that Bahraini leaders be wise and not use violence in their handling of anti-government protests, the state-run Fars news agency reported.
Salehi said the Bahraini authorities should avoid using "violence and force against the population", adding that Iran expects "the Bahraini government to be wise in responding to the demands of protesters and respecting their rights."
Although there were no signs Shiite-led Iran was behind unrest in the Gulf kingdom or elsewhere in the region, Tehran would likely work to meddle in Bahrain's politics amid sectarian tensions, Gates said.
"I expressed the view that we had no evidence that suggested that Iran started any of these popular revolutions or demonstrations across the region," said Defense Secretary Robert Gate.
The move of dispatching GCC troops to neighboring Bahrain come after Bahraini police clashed on Sunday with mostly Shiite protestors in one of the most violent confrontations since troops killed seven protesters last month.
The Financial Harbor business complex was blocked off by protesters on Sunday a day after more than 200 people were injured there in clashes between riot police and demonstrators, residents said.
Britain's foreign office cited reports that the Saudi National Guard will enter Bahrain as it urged Britons to avoid all travel to the mainly Shiite archipelago, where the Sunni monarchy is under mounting pressure to reform.
"The risk of further outbreaks of violence has increased," it said in the note issued late Sunday.
Witnesses said Shiite-led protesters continued to hold a sit-in at Pearl Square just outside the financial district, while others were blocking the main highway leading to the business district.
Crown Prince Salman reiterated the government's offer of a national dialogue on deep-rooted reforms but not at the expense of security and stability, state news agency BNA reported late Sunday.
The prince supported the creation of a parliament with full powers, and also pledged to tackle corruption and sectarian tensions.
But he warned that "legitimate demands should not be carried out at the price of security and stability."
The United States condemned the violence.
"We urge the government of Bahrain to pursue a peaceful and meaningful dialogue with the opposition," White House spokesman Jay Carney said.
Bahrain -- home of the U.S. Fifth Fleet -- has become a regional financial hub as it seeks to diversify its economy away from a dependence on diminishing oil revenues.
King Hamad also reiterated an offer of dialogue with the main opposition groups, which have refused to negotiate until the government resigns and dissidents are released from jail.