BEIJING, Aug 4 (Reuters) - Flash floods in just one county in central China killed 78 people and left at least 18 missing, state media said on Saturday, as hundreds of firemen struggled to control forest fires in the north.

Lushi county, in the west of the province of Henan, was hit by continuous torrential rain last week. Xinhua news agency said it triggered flash floods and disrupted transport, power, communications and other facilities in 10 townships.

The floods destroyed more than 6,000 houses and more than 6,667 hectares (26 sq miles) of crops.

Hundreds of police and firemen meanwhile were struggling to douse forest fires in the northern Chinese region of Inner Mongolia, Xinhua said.

"Three fires had been detected by satellite data in the virgin forests north of the Greater Hinggan Mountain," the region's meteorological administration was quoted as saying.

Nine people were killed as storms ravaged the eastern province of Anhui on Thursday and Friday. Five were crushed when a two-storey building collapsed after being struck by lightning.

Two other cities in the province each reported a death from lightning strikes.

Lightning has killed at least 403 people in China this year, equivalent to the total for the whole of 2006, the China Meteorological Administration said.

Floods across the country have killed more than 700 people this summer, while millions elsewhere faced shortages of drinking water as high temperatures exacerbated drought.

In a bizarre but frequent disaster in Zhejiang province in the east, at least eight people were dead and three missing after a tidal bore swept away more than 30 people near the mouth of the Qiantang River on the outskirts of Hangzhou.

The victims and the 22 who were rescued had been either swimming or walking along a T-shaped levee.

The tides on the Qiantang always attract spectators. Scientists say that the trumpet-shaped mouth of the river helps form the tidal change, which can be as high as 3.5 metres.

AlertNet news is provided by