A Saudi police officer checks cars at a security checkpoint in Saudi Arabia's eastern Gulf coast town of Qatif November 25, 2011. The Saudi government stepped up security after two people were killed and three wounded in an exchange of gunfire in oil-producing eastern Saudi Arabia between security forces and what the government called gunmen serving a foreign power. REUTERS/Fahad Shadeed (SAUDI ARABIA - Tags: POLITICS CIVIL UNREST CRIME LAW)