MOSCOW - A strong 6.8 magnitude earthquake hit Russia’s southeastern and sparsely populated region of Tuva on Sunday, shaking residents near the Mongolian border from their sleep, but there were no immediate reports of injuries or damage. The US Geological Survey said the epicenter of the quake was some 90 kilometers east of the Russian city of Kyzyl in the Tuva region of Siberia. It struck around 0617 GMT at an estimated depth of 11.7 km. It was the second strong quake to rock the region in two months. Residents gathered outside as the local emergencies ministry warned of potential aftershocks.