Sea ice along Liaodong Bay and the Yellow Sea will continue to expand due to a fresh round of cold air, the State Oceanic Administration (SOA) has forecast.

The administration yesterday issued the latest sea ice warning as areas up to 160 km from the bank of Liaodong Bay had been covered with floating ice by Wednesday night.

The sea ice is expected to reach areas up to 170 km from the bank in the next five days, with ice measuring about 40 cm thick.

Local authorities have been urged to ensure safe and smooth navigation at sea and operations at ports.

"The latest sea ice warning is mainly targeting the expanding ice along Liaodong Bay. However, the sea ice at Laizhou Bay and Bohai Bay remains stable," said Guo Kecai, a weather forecaster with the administration.

The National Meteorological Center also issued a cold wave warning yesterday for the northwestern, northern and central regions of the country.

The forecast said that in the next 10 days, rain and snowfall will dramatically increase in the regions.

From next Monday to Thursday, the central and eastern parts of China will also embrace a cold wave, which is expected to reduce the temperature by up to 10 C.

Gales and fog were also forecast for the north Yellow Sea and East China Sea, national forecasters said on the website of the China Meteorological Administration.

The coming cold may worsen the severe sea ice along China's eastern and northern coastal line.

The worst sea ice in three decades on the country's eastern coast has been threatening shipping and the livelihoods of fishermen since late last year.

The floating ice since late last year has caused more than 2.2 billion yuan ($323 million) of economic losses in Shandong province and more than 330 million yuan in Dalian, Liaoning province so far, the Xinhua News Agency reported last month.

Juhua Island, the largest island in Liaodong Bay, was surrounded by sea ice, which caused more than 3,200 residents on the island to face coal and medicine shortages.

The Ministry of Transport called for efforts to reduce accidents caused by sea ice to guarantee the safe navigation on the sea early last month.

Huludao, a coastal city in Liaoning, also faced the worst sea ice in three decades. The sea nearby froze a month earlier than usual with sea ice reaching a length of 110 km from the bank last month, data from the SOA showed.

The Shandong provincial oceanic and fishery department issued warnings of sea ice and began 24-hour monitoring of sea conditions last month.