GUANGZHOU -- The number of dengue cases in south China's Guangdong Province has risen by 36 since Tuesday to 124, said the provincial health bureau on Thursday.

Thirty-eight news cases were reported over the past two days, but two earlier reported cases had been excluded, according to the bureau.

Thirty-six new cases were reported in the provincial capital of Guangzhou, and one each in the cities of Foshan and Yangjiang.

Sixty-three patients had recovered and the others were reported to be stable in hospital.

Five cases involved people from Indonesia, Cambodia, Malaysia and Thailand, and the rest were all local residents, said the bureau.

Dengue is a serious infectious disease transmitted by mosquitoes. It kills 25,000 people and infects more than 100 million each year in tropical and subtropical regions worldwide, according to China's Ministry of Health.

Since the 1990s, dengue has broken out occasionally in Guangdong and neighboring Fujian province, mostly on a small scale. Large outbreaks took place in Fujian in 1999 and in east Zhejiang province in 2004.

The local health bureau has called residents to clean up their environments to eradicate mosquitoes as there are no effective vaccines to prevent the disease.

The ministry has announced a nationwide monitoring of dengue to gather details of epidemic conditions and analyze dissemination patterns so the disease can be detected rapidly and treated.

Sixteen monitoring sites will be set up in the southern provinces of Guangdong, Fujian, Yunnan, Hainan and Guangxi Zhuang Autonomous Region.