Retirees in the central Chinese city of Wuhan and the northeastern city of Dalian took to the streets last week to express their outrage over the local government’s curtailing of medical insurance coverage.

Photos and videos of demonstrations circulating online show crowds of senior citizens gathering in various areas of the two cities, including a local hospital and park in Wuhan and a public square outside a district government building in Dalian. Some protesters can be heard singing “The Internationale.” A heavy police presence is seen in several video clips, but it remains unknown whether police have arrested any protesters as a result of the demonstrations.

Seniors participating in the rallies are protesting against proposed changes to the country’s medical insurance system.