BEIJING/TAIPEI - China's National Marine Environmental Forecasting Center on Sunday downgraded Nanmadol from a strong to a normal strength typhoon.

Residents are evacuated on an excavator in Hengchu township of Pingtung county in southern Taiwan in this handout photograph taken August 28, 2011. Taiwan has issued a warning to residents of its southern and eastern regions as powerful typhoon Nanmadol approaches after hitting the northern Philippines. [Photo/Agencies]

Nanmadol was located 70 km southeast of the southernmost tip of Taiwan at 6 pm Sunday and was moving north at a speed of 12 to 8 km per hour. It was expected to make landfall in Taiwan Monday, Taiwan's local weather bureau said.

Taiwan authorities issued land and sea warnings Sunday afternoon and thousands of people have been evacuated.

Offices and schools in many places, such as Taitung and Hualien, were colsed from Sunday afternoon and Monday. The island's forestry bureau said all the forest parks should also be closed.

From Sunday night to Monday, Bashi Channel, off the southeast coast of Taiwan, will see waves of 6 to 8.5 meters, the South China Sea and the Taiwan Strait will see waves of 4 to 6 meters, and waters off Zhejiang, Fujian and Guangdong  provinces will see waves of 2 to 3 meters, according to China's National Marine Environmental Forecasting Center.

The center is continuing its yellow alert for the storm, warning local authorities and the public to take precautions and intensify safety checks on fishing facilities.

The yellow alert is the second-lowest alert level in the country's four-level rainstorm alert system.