A sand storm, the first of this year, hit north China's Inner Mongolia Autonomous Region on Thursday, the central and regional meteorological stations said.

It started at 10 a.m. in Xilingol, in the central part of the region, then spread 57,000 square kilometers. It reduced visibility to less than 800 meters.

The sand storm expanded and moved eastward Thursday afternoon, affecting northern Hebei Province.

"Sand storms generally occur between February and May in China," said You Li, vice director with the regional meteorological bureau.

"Sand storms last about 10 days in Inner Mongolia. This year it is expected to be the same as last year," she said.

According to an earlier report, the State Forestry Administration warned that the persistent drought in north China, the worst in 50 years, could damage forests, thus making spring sand storms worse.

(Xinhua News Agency February 20, 2009)