Authorities said a fourth police officer died following a suicide car bombing in the Russian republic of Dagestan in the North Caucasus, Thursday. Police previously reported three officers and the bomber died in the incident, but a fourth officer was later found dead. RIA Novosti said the bomber detonated the bomb at 5 a.m. when police stopped his car at a checkpoint outside the city of Khasavyurt. Authorities said the explosives left a crater four feet deep. RIA Novosti said the investigative committee has opened a criminal case on terrorism charges, but no one immediately claimed responsibility for the attack.