QINGDAO, Shandong, Jan. 10 (Xinhua) -- The most severe icing situation in the past 30 years in the coast off east China's Shandong Province continued to worsen amid cold snaps, oceanic officials said Sunday.

    Sea ice appeared last week along the coastline of the Bohai Sea and northern Yellow Sea as cold fronts pushed the temperature down to minus 10 degrees Celsius, said Guo Kecai, deputy general engineer of the North China Sea Branch (NCSB) of the State Oceanic Administration.

A mariculturist breaks the ice on the sea in Jiaozhou, east China's Shandong Province, Jan. 10, 2010

The outer edge of the ice sheets in the Liaodong Bay, Bohai Bayand northern Yellow Sea extended 60 nautical miles, 15.5 nautical miles and 20 nautical miles, respectively, according to the NCSB.

    With another cold front expected Monday, the sea ice along the coastline would further develop, experts said.

    More than 200 fishing boats were frozen at a port in Dongying Village in the Jiaozhou Bay. Fishermen said the ice sheet could be20 cm to 30 cm thick.

Police help move the vessels stucked by ice in Qingdao, east China's Shandong Province, Jan. 10, 2010

In the waters near Liaodong Bay and Laizhou Bay, floating ice was reported in an area of 65 to 75 nautical miles, with ice measured more than 50 cm thick, threatening ship navigation, anchoring and operations at ports, Transport Minister Li Shenglin said Saturday.

    The NCSB had strengthened monitoring on icing conditions and sent warnings to local residents and governments.