At least 56 people have been killed and 22 are missing as heavy rains pummeled southern China, flooding towns, cutting off power and destroying houses, officials said on Tuesday.

Water levels in more than 60 different rivers have risen above warning levels, forcing more than 1.2 million people to evacuate.

Authorities said more than 38,000 homes have collapsed and nearly 880,000 hectares of crops have been damaged.

The Chinese government said it has disbursed $103m in emergency aid so far to help southern and central provinces deal with the flooding.

The annual floods have been even greater than normal and the past week has been particularly wet.

IN PICTURES: Floods in China kill scores, displace tens of thousands

Changsa, the capital city of the province of Hunan, recorded nearly half a metre of rain in a week. This amount is well above the average and is nearer what could be expected on average throughout June, July, August and September put together.

Across Hunan, the flooding has forced hundreds of thousands of people to evacuate, damaged crops and destroyed houses, causing a total direct economic loss of $1.22bn, the provincial civil affairs office said.

The river Laodao, a tributary to the mighty Yangtse, exceeded its previous depth and set a new record. At nearly 40 metres, it required a 5km sandbank levee in a failed attempt to save Changsa from flooding.

Rising water levels left Orange Isle, a popular tourist destination in Changsha, almost completely submerged, with only roofs and trees peaking out above the floodwater.

The Yangtse itself, Asia's longest river and with a capacity to match, has burst its banks in Hunan.

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According to the State Flood Control and Drought Relief Headquarters, continuous, heavy rain that started in mid-June has caused the water of 10 major tributaries of the Yangtze, as well as 89 middle and small-sized ones, to rise to record levels.

Over the past two days, the seasonal monsoon rainband, the meiyu-baiu front, has eased off in Hunan but reinvigorated in the southwestern province of Guangxi.

The water levels in the rivers of northern Guangxi are now a major concern, most having exceeded the warning line.

The forecast for the next couple of days sees much reduced rainfall in the currently flooded areas, although another 100mm is still possible in Anhui.

More worryingly, the area likely to receive heavy rain next is in Sichuan province, in the area of a recent fatal mountainside collapse.