Iranian security forces have put a violent end to demonstrations in Tabriz and Oroumiyeh, arresting dozens of protesters who were speaking out against the government’s inaction as Lake Oroumiyeh rapidly dries out.

Protesters in Oroumiyeh condemned “the government’s policy of drying out Lake Oroumiyeh.” The Association for the Defence of Azerbaijani Political Prisoners reports that the gatherings were attended by thousands of protesters. According to eyewitnesses, the government forces used tear gas bombs and batons to disperse the crowd, injuring and arresting dozens of protesters.

Families of the detainees have told Radio Zamaneh that authorities aren’t saying where they’re being held.

Earlier, 22 Iranian MPs called for immediate action regarding the critical situation at Lake Oroumiyeh, which is quickly becoming a salt field, a process that has been accelerated by the numerous dams built on the rivers that feed it.

The government has so far confronted public outcry in the region by arresting activists.