CARACAS (Reuters) - Venezuelan opposition leader Juan Guaido said on Monday that security forces had "threatened" him with arrest at his apartment building, and an opposition spokesman said a close Guaido ally had been arrested.

       Guaido's wife, Fabiana Rosales, earlier said that security forces had entered their apartment building in an attempt to detain Guaido. Guaido later told reporters gathered outside their Caracas building that the forces had departed.

       "The harassment and the threats will not stop us," said Guaido, who in 2019 was recognized by dozens of countries, including the United States, as Venezuela's legitimate head of state on the basis that President Nicolas Maduro had rigged his 2018 re-election.

       Earlier on Monday, security forces arrested opposition lawmaker and close Guaido ally Freddy Guevara, according to a spokesperson for Guaido's office, adding that Guevara was taken to the Helicoide prison in Caracas.

       Venezuela's information ministry did not immediately respond to a request for comment.

       Maduro labels Guaido a U.S. puppet and accuses him of conspiring to oust him in a coup.

       (Reporting by Vivian Sequera and Sarah Kinosian; Writing by Luc Cohen; Editing by Rosalba O'Brien)