Buenos Aires: A man claiming to have a bomb threatened to blow up a building six blocks from the Argentine presidency hours before US President Barack Obama visited it on Wednesday, witnesses said.
Police arrested the man and evacuated the building housing a state radio station, employees of the broadcaster told media. No one was reported hurt.
The man threatened to blow up the National Radio building in central Buenos Aires, where security forces were on high alert a day after deadly bombings in Brussels.
"There was a scuffle and yelling in the lobby. He got to the entrance of the studios and yelled, 'We are going to blow you all to hell,'" one employee of the station, identified as Enrique, told television channel CN5.
"He had what looked like a detonator in his hand, with a trigger."
Another of the company's journalists, Eduardo Anguita, said: "He came into the radio station pretending to have a bomb belt. That caused anxiety. It was to scare people after the Brussels attacks and while Obama is here."
Representatives of the radio station said the police detained a man in his 50s.
The station went off the air. The building is located six blocks from the Casa Rosada presidential palace. Obama met there later with Argentine President Mauricio Macri.
US President Barack Obama urged nations to unite against terrorism and said wiping out IS was his "top priority".
White House hopeful Hillary Clinton took a harsher tone, criticising Europe's intelligence cooperation, saying it "still lags" despite pledges made after last year's Paris attacks.
"There's also more they can do to share the burden with us," Clinton added.
US Secretary of State John Kerry is to visit Brussels on Friday to offer Washington's support and issue condolences.