HONG KONG (AP) — Companies including the Chinese arm of TripAdvisor Inc. have been ordered by regulators to overhaul their mobile phone apps in what the Chinese government said is a crackdown on pornography and other improper content.

The National Cyberspace Administration ordered the removal of 105 apps including TripAdvisor from app stores this week, although it gave no details of what each app was accused of doing wrong. It cited what it said were public complaints about obscene, pornographic and violent information or fraud, gambling and prostitution.

The ruling Communist Party tightly controls what the Chinese public sees online and has launched repeated crackdowns on websites and apps.

TripAdvisor China, a joint venture between TripAdvisor and its Chinese partner Trip.com, did not immediately respond to an email seeking comment.

Following the removal of its app in China, Nasdaq-listed TripAdvisor’s stock price was down 1.68% to $29.59 at the market's close in the U.S. on Tuesday.

TripAdvisor owns a 40% stake in TripAdvisor China, with Trip.com owning the other 60%. Under the partnership, the companies share its travel inventories and content.

Associated Press writer Joe McDonald in Beijing contributed to this report.