A strong, shallow 6.6-magnitude quake shook south-western Siberia on Tuesday some 58 miles (94 kilometers) east of the Russian city of Kyzyl, US seismologists said. The quake, which struck at 10:21 pm (1521 GMT), hit at a depth of 3.7 miles (six kilometers), the US Geological Survey said in a statement. The epicenter of the quake was in a sparsely populated region near the border with Mongolia.