Cuban police detained several dissidents on Tuesday and thwarted an unauthorized political protest, dissidents said, in the first major test of U.S. President Barack Obama's policy shift toward normalizing relations with the communist-ruled island.

The U.S. State Department condemned the detentions, which marked the most significant crackdown on the opposition since Cuba and the United States agreed on Dec. 17 to restore diplomatic ties and put behind more than five decades of hostility.

About 12 opponents were taken away by police, including the husband of opposition blogger Yoani Sanchez, while several others were told not to leave their homes as police parked outside, said Elizardo Sanchez, leader of a dissident human rights commission that monitors such detentions.