MOSCOW (AP) - Seven mountain-climbers, including three Britons, have been killed in an avalanche in the Russian Caucasus, emergency officials said Tuesday. The mountaineers were climbing the Uzhba peak in the Elbrus range near Russia's border with Georgia when an avalanche struck, said Natalia Shakhgedanova, a spokeswoman for the Emergency Situations Ministry in Moscow. She said that the regional ministry branch had informed the Moscow office of the catastrophe on Monday evening, but she was unsure when the avalanche had occurred. A ministry spokeswoman had said earlier that the climbers had gone missing on Monday.