China has issued an orange alert to ships and fishing vessels, its second-highest alert level, the official Xinhua news agency said on Thursday, adding that Muifa was expected to be one of the most powerful typhoons to hit China in recent years.
Shanghai is the world's largest container port. An official at one of the city's ports, Waigaoqiao, told Reuters the port authority was monitoring the situation and would close operations if the typhoon's impact was serious enough.
Jinbao, a local newspaper in Zhejiang province run by Xinhua, said that authorities in the port city of Ningbo had ordered fishing, passenger and other vessels to dock by Thursday evening because of the large waves expected.
Provincial authorities were also preparing for the possibility of having to evacuate people from coastal areas, according to a notice on the central government's web portal, www.gov.cn.
Muifa, which was approaching Okinawa in southwestern Japan as of 09:30 GMT on Thursday, prompted Japanese refiner Nansei Sekiyu KK, wholly owned by Brazil's state-run Petrobras, to suspend marine operations at its 100,000 barrel-per-day Nishihara refinery from late Wednesday.