Official: Gulf military force enters Bahrain

photo A man pours cola over the face of a demonstrator who was overcome by the effects of tear gas, to help counter the effects of the gas, during clashes between police and anti-government demonstrators Sunday, March 13, 2011, in Manama, Bahrain. Riot police in Bahrain fired tear gas and rubber bullets at anti-government demonstrators blocking the highway into the capital's financial district Sunday and surrounded the protesters' main camp in the capital, eyewitnesses said, although they failed to dislodge the thousands of protesters blocking the highway. (AP Photo/Hasan Jamali)

BRIAN MURPHY, Associated Press

REEM KHALIFA, Associated Press

MANAMA, Bahrain - A military force from Saudi Arabia and other Gulf nations moved into Bahrain Monday to shore up the nation's Sunni rulers in the face of escalating Shiite-led protests seeking to break the monarchy's hold on power.