CHONGQING -- Yangtze River's water level in Chongqing municipality exceeded historical high early Thursday morning, posing unprecedented threat to the metropolis in Southwest China.

At around 8 am Thursday, the water level at the Cuntan hydrologic station in Chongqing reached 191.55 meters, 0.14 meters higher than the record in 1981, and was rising.

Chongqing, located in the upper reaches of China's longest river, upgraded its flood-control response to Level-I on Tuesday, the highest rung in the four-tier emergency response system for floods.

Although there has been no rain lately in Chongqing, due to recent heavy downpours in the Sichuan Basin in the upper reaches of the Yangtze River, the city was flooded on Monday.

Chongqing sits at the confluence of the Yangtze and its tributary Jialing River. "This flood is the combined outcome of the second flood of Jialing River and the fifth flood of Yangtze River," said Wang Shiping of the municipal emergency management bureau.

Chongqing is called a "mountain city" for its hilly landscape, with mountains accounting for 76 percent of the area and hills for 22 percent. Meanwhile, the water system in the city is dense.

"The special topography makes disaster caused by floods frequent in Chongqing," said Wang.

Popular tourist destination Nanbin Road, city landmark Chaotianmen Port and ancient town Ciqikou have all been badly hit.

Latest statistics show that the floods have affected more than 260,000 people in Chongqing, and flooded over 20,000 shops.

As of 8 am Thursday, the floods have caused economic losses of 2.45 billion yuan (about $354 million), said the flood control and drought relief headquarters of Chongqing.

More than 250,000 residents of Chongqing have been evacuated to safe places.