Relatives of passengers missing in the sinking of the Eastern Star cruise ship on the Yangtze River have accused Chinese police of beating them when they sought more information about the disaster.

Uniformed police trailed dozens of relatives who took to Shanghai's streets on Wednesday in the hope of petitioning the city government, later ushering them into a building where they were prevented from speaking to the media, the family members said.

Scuffles between police and relatives broke out, according to video footage circulated on the Internet which showed police hitting and wrestling family members.