An earthquake measuring 5.1 on the Richter scale today jolted southwest China's Yangbi County. The epicentre of the quake was located in the county's Ajia and Puping villages, where some houses were reportedly damaged, said Wang Caixun, a publicity official of Yangbi County in Yunnan Province. Fire fighters and medical teams are heading to the villages, Wang said. The epicentre was monitored at\u00a0a depth of about 12 kilometres, China Earthquake Networks Centre said. Four tremors measuring 3 to 4.7 on the Richter scale hit the same region before and after the quake, the centre said. There were no reports of any casualties, state-run Xinhua news agency reported.