Bahrain, officially the Kingdom of Bahrain is a borderless island country in the Persian Gulf .
Saudi Arabia lies to the west and is connected to Bahrain by the King Fahd Causeway (officially opened on November 25, 1986)and
Qatar is to the south across the Persian Gulf. The Qatar–Bahrain Friendship Bridge, currently being planned, will link Bahrain to Qatar as the longest fixed link in the world.
Thousands of supporters of Bahrain's Shiite-led opposition poured into a Manama square calling for the government's downfall in the largest rally in more than a week of protests.
Those leading the protest carried a large banner reading, "The march of loyalty to martyrs" which bore the pictures of seven protesters killed by security forces.
Another poster strung from a bridge read in English, "No dialogue before the downfall of the ruling regime".
"The people want the fall of the regime," protesters chanted in unison, waving red-and-white Bahraini flags as they swarmed into Pearl Square
Thousands of anti-government demonstrators cut off Bahrain's financial center and drove back police trying to push them from the capital's central square - shaking the tiny island kingdom Sunday with the most disruptive protests since calls more freedom erupted a month ago.
Demonstrators also clashed with security forces and government supporters on the campus of the main university in Baharain
The clashes fueled fears that Bahrain's political crisis could be stumbling toward open sectarian conflict between Sunnis and Shiites, who account for 70 percent of the nation's 525,000 people
Bahrain's rulers asked neighbouring Arab states to send troops to help quell the violent protests that have raged for a month and escalated again this week.
Anti-govt protesters shout slogans at Riot Policemen as they block a road in Manama.
Saudi Arabia, Kuwait, Oman, Qatar and the United Arab Emirates have all responded to the request by sending troops.Bahrain's rulers have offered to hold talks with opposition leaders but so far it has not been enough to satisfy the protesters' demands
Saudi Troops Crossing the causeway leading to Baharain
Forces from the Gulf Cooperation Council (GCC) arrived in Baharain
The GCC forces are expected to protect strategic facilities, such as oil, electricity and water installations, as also financial and banking facilities.GCC comprises Bahrain, Saudi Arabia, Kuwait, Qatar, United Arab Emirates (UAE) and Oman.
Bahrain govt loyalists ask king to impose martial law