A 184-kilometer ice run was sighted on Friday in the upper section of the Yellow River, China's second longest, in an area flowing through the northwestern Ningxia Hui Autonomous Region, according to regional flood control authorities.

The Ningxia Flood Control and Drought Relief Headquarters said that the ice run appeared about half a month later than in recent years. The Yellow River's ice formations usually persist from mid-December to February.

According to the headquarters, the ice consistency averaged 30 percent in the stretch, and it ran down the river with cracking sound.

A 225-km section in the middle of the river near Hohhot, the capital of Inner Mongolia Autonomous Region, has frozen.

The regional flood control authorities said that the frozen stretch was expanding by about 30 km a day, slower than normal years, because recent temperatures had been around 2 degrees Celsius higher than that recorded during the same period in normal years.

Sections of the Yellow River freeze and thaw at different times. When an ice run flows to a frozen section, it can be blocked. If the blockage persists, water levels may rise and cause floods and dam bursts, threatening lives and property. Flood control authorities along the 5,464-km Yellow River are conducting round-the-clock surveillance against a possible ice flood of the river.

The Yellow River originates in Qinghai Province in the northwest and flows through Gansu, Ningxia, Inner Mongolia, Shaanxi, Shanxi and Henan, before emptying into the Bohai Sea.

(Xinhua News Agency December 28, 2007)