The death toll has risen to 615, four days after a powerful earthquake devastated parts of southwest China's Yunnan Province, local authorities said on Thursday.

Among the reported deaths, 526 were in Ludian County and 76 in Qiaojia County. The quake also caused one death in Zhaotong City and another 12 in Huize County.

In addition to the deaths, 114 people are missing and 3,143 were injured, 343 of whom are in a critical condition. More than 80,000 houses collapsed and 129,100 were damaged. A total of 229,700 people have been evacuated.

According to the provincial civil affairs department, Yunnan has accepted more than 332 million yuan of monetary donations (about 54 million U.S. dollars) and supplies worth over 100 million yuan. A total 1,129 rescuers have been sent to the quake zone, 366 of whom are epidemic prevention personnel.

High temperature and lack of medicines have complicated the post-disaster epidemic control, according to a health official.

"We collect 14 water samples in the quake zone, which show high risk of enteric infectious disease," said Xu Heping of the provincial health department.

The 6.5-magnitude earthquake, the strongest to strike Yunnan in 14 years, occurred at 4:30 p.m. Sunday (Beijing Time) with its epicenter in Longtoushan Township, Ludian County in Zhaotong City, affecting over 1.08 million people in the cities of Zhaotong and Qujing.