The activists have been inside the embassy because they consider Nicolas Maduro the legitimate president of Venezuela. The U.S. and 50 other countries say Maduro's reelection was fraudulent and have recognized opposition leader Juan Guaidó as Venezuela's interim president.
Gustavo Tarre, Venezuela's representative to the Organization of American States, told The Associated Press that after the eviction notice was served, three activists left the building. Four remained, Tarre said.
Brian Becker, national director of the Answer Coalition, which supports the activists, said those still inside the building will not leave voluntarily. He said police cut the chains that were locking the front gate and handed the order to activists who came to the ground level to meet them.
Rafael Alfonso, director of operations for the embassy, said it appeared unlikely that the remaining activists would be removed from the embassy Monday night and that the situation would be revisited sometime on Tuesday. Alfonso said once the building had been cleared of activists, he would assess any damage on behalf of the embassy.
It was not clear Monday night which U.S. agency issued the eviction notice, though Secret Service agents and District of Columbia police surrounded the embassy.
Carlos Vecchio, whom the U.S. recognizes as Venezuela's ambassador, tweeted that "next steps" will be announced soon.