Chinese police said Wednesday they had freed 89 children in a crackdown on trafficking launched this year after online reports of widespread abductions sparked public outrage. Police also arrested 369 people in the six-month operation to break up a pair of \"large criminal enterprises\" involved in child-trafficking across 14 provinces, the Ministry of Public Security said in a statement. \"Two large criminal gangs involved in child-trafficking have been successfully destroyed, once again showing the public security organs\' solemn commitment to the people,\" it said. Children were sold for an average of about 40,000 yuan ($6,210), it added, but otherwise gave few details. Abductions and human trafficking have become serious public concerns after a string of revelations, including a shocking 2007 scandal in which thousands were forced into slave labour in brickyards and mines across the nation. Some Chinese academics have blamed the country\'s \"one-child\" policy, which is aimed at controlling growth in China\'s population, the world\'s largest at 1.3 billion, for contributing to child trafficking. The policy generally limits people in urban areas to one child, while rural families can have two if the first is a girl. This has put a premium on baby boys, and baby girls have been sold off or abandoned as couples try for a male heir. The issue leapt back onto the national agenda at the beginning of the year when a professor known for his activism on behalf of China\'s downtrodden classes launched a microblog that helps parents find missing children. The campaign by Yu Jianrong, a professor of rural development, went viral as hopeful parents jumped at the chance of finding missing kids, prompting the government to issue a new crackdown pledge. The microblog allows parents to upload photos of missing children and seek help from other Web-users in finding them.