The Shanghai Central Meteorological Observatory on Wednesday afternoon upgraded an earlier yellow rainstorm alert to orange, the second highest warning level.

Typhoon Co-May made landfall in eastern Zhejiang Province at about 4:30 am Wednesday (2030 GMT Tuesday), and is expected to make a second landfall in financial hub Shanghai in the evening.

"From last night to 10:00 am today, 282,800 people have been evacuated and relocated, basically achieving the goal of evacuating all those who needed to be evacuated," state broadcaster CCTV reported.

Live shots from China's coast showed waves overrunning seaside walkways, while broadcasts from the city of Ningbo showed residents splashing through ankle-deep water.

Separately, China issued a tsunami warning for parts of the eastern seaboard after a magnitude-8.8 earthquake struck off Russia's Kamchatka Peninsula.

However, the warning was later lifted, according to CCTV.