One person was killed and 324 were injured when an earthquake with a magnitude of 6.4 struck in China's southwestern province of Yunnan on Tuesday.The United States Geological Survey said the quake's epicentre was 163 km (100 miles) north-northwest of Yunjinghong and 10 km deep.The official Xinhua news agency said tremors could be felt in the provincial capital of Yunnan, Kunming, as well as several other major cities in the province.