Thai police say they have arrested six people accused of being part of a conspiracy to slander the country's monarchy on the Internet.

Police say the six belong to a group called the Banpodj Network which allegedly spread anti-monarchy propaganda over social media. A police statement on Tuesday described the network as a serious threat to the monarchy and the nation's stability.

The military junta that seized power in a coup last May has made protecting the monarchy's reputation one of its priorities. It vigorously pursues those suspected of disloyalty to the crown. Insulting the monarchy is punishable by three to 15 years' imprisonment.

The prospect that instability will ensue when 87-year-old King Bhumibol Adulyadej ends his long reign is a matter of widespread concern.