Cuban police arrested protesters and independent journalists Tuesday just hours before a planned rally for free speech in Havana’s Revolutionary Square, according to Reuters. The arrests come just two weeks after U.S. President Obama announced steps to revive full diplomatic relations with the island nation and condemned penalties against Cubans for expressing their views.

The event’s organizer, Tania Bruguera, has been reported missing by friends and family since early Tuesday morning, NBC News reported. “Those who know Tania know she must have fought hard to be taken from her home,” the woman’s sister, Deborah, reportedly posted on Facebook.

Bruguera, a well-known performance artist in Cuba, had dubbed the rally #YoTambienExijo, which in English means #IAlsoDemand. The event was scheduled to be an open-microphone setup where participants could express their views about the future of Cuba.

Several other opposition activists were also arrested or put under house arrest before the unauthorized protest was scheduled to take place. Yoani Sanchez, a well-known blogger and founder of the dissident news website 14ymedio, is reportedly under house arrest. The editor-in-chief of 14ymedio Reinaldo Escobar, who is Sanchez’ husband, was arrested outside their home along with dissident leader Eliecer Avila early Tuesday afternoon.

Ric Herrero, the executive director of a pro-democracy group called #CubaNow, condemned the arrests in Havana. “Today’s detentions in Havana are a reminder that change won’t happen overnight in Cuba, and that it is Cuban voices that can most effect change in their country,” Herrero said in a statement Tuesday. “The Cuban government must understand that people have the right to express themselves, even when they disagree with their government.”

Cuban President Raul Castro praised Obama’s policy change in U.S.-Cuba relations but demanded the United States respect Cuba’s communist rule, according to Reuters. "In the same way that we have never demanded that the United States change its political system, we will demand respect for ours," Castro reportedly told the National Assembly in Havana on Dec. 20.