Police in China's eastern province of Jiangsu have begun an investigation after at least 145 children received expired polio vaccines, the Global Times said on Monday, a new blow to a sector hit by a series of scandals last year.
Residents, including the children's parents, blocked traffic and disrupted public order as they gathered outside Jinhu county offices on Friday, said the paper, which is published by the ruling Communist Party's People's Daily.
Three have been arrested, police said in a statement.
The vaccine was administered on Jan. 7, despite an expiry date of Dec. 11, the paper said, adding that local government authorities have set up a special investigation team to look into the matter. It said 17 people had already been punished.
China, which has repeatedly pledged to crack down on companies and officials involved in food and drug scandals, on Sunday said food safety and health would be a major priority of its anti-graft campaigns this year.
China vaccine maker Changsheng Bio-technology Co Ltd was embroiled in a scandal last year after it was found to have falsified data for a rabies vaccine. It faces penalties of 9.1 billion yuan ($1.35 billion).