China tightened its control over the distribution of news by foreign agencies Sunday, further restricting international access to the already tightly regulated Chinese media market. The new measures took effect immediately upon being issued by the state Xinhua News Agency. The regulations give Xinhua broad authority over foreign news agencies, requiring them to distribute stories, photos and other services solely through Xinhua or entities authorized by Xinhua. The rules would affect The Associated Press, Reuters and other foreign news agencies seeking wider access to the rapidly expanding Chinese market. It was unclear how other news organizations would be affected. Under...