More than 130 companies are involved in producing or trading the equipment, typically marketed to law enforcement agencies, up from about 28 companies a decade ago, Amnesty said.<br/> <br />The equipment fuels human rights abuses by law enforcement authorities in African and Southeast Asian states, the group said in a report.<br/> <br />One company, China Xining Import/Export Corporation, which advertises thumb cuffs, restraint chairs and electric stun guns, said in 2012 it had ties to more than 40 African countries, according to Amnesty.<br/> <br />The firm could not be reached for comment.<br/> <br />The rights group worked with the British-based Omega Research Foundation, which researches the trade and the use of military, security and police equipment.<br/> <br />China's Foreign Ministry could not be immediately reached for comment.
