A national lawmaker was shot and injured near the Congress building on Thursday morning, as gunmen attacked deputy Héctor Olivares and a fellow La Rioja provincial government official.
The official, later identified as Miguel Marcelo Yadón, died of the wounds sustained in the attack.
Two men shot at Olivares from inside a vehicle, police reported. Yadón's death was confirmed by ambulance authorities.
Olivares, who represents La Rioja province for the UCR Radical Party, had on Wednesday participated in a debate in Congress on a law to limit the criminal activity of the barra brava, Argentina's powerful football hooligan groups. So far, authorities have not established any connection between the shooting and the debate.
The two officials were taken by ambulance to Ramos Mejía Hospital, the SAME ambulance service's chief Alberto Crescenti reported.
Olivares was taken into surgery. His condition remained unknown at present, Crescenti told the Todo Noticias news station.
Yadón, a Transport Secretariat official for the La Rioja provincial government, died before arrival at the hospital.
Several 911 calls were made regarding gunshots in the area close to the National Congress building in Buenos Aires' downtown, Perfil reported in the aftermath of the attack.
Two police vehicles attended the scene, where they found Olivares and Yadón. According to reports, one man suffered an injury to the abdomen and the other was hit in the leg.
Authorities do not believe the incident was a failed armed robbery since the vehicle departed immediately after the shooting, Perfil reported.
The case is in the hands of City prosecutor Estela Andrade de Segura who must decide in consultation with Federal Judge Ariel Lijo if the jurisitiction of the investigation should be federal, since it involves a national lawmaker.
Olivares was hit with three bullets and is in surgery, his spokesman Hector Lencinas said.
Yadón, 58, took multiple hits and died, lawmaker José Cano told television station Canal TN.
"We never received any threats of any type in the office. It's an open office were everyone is welcomed. [Olivares] was very calm," Lencinas told reporters.
Cano called the shooting a "premeditated act."
"The information we have is that the car was parked half an hour before, they were waiting for [Olivares] because he would go out for a walk in that place every day with Yadon," said Cano.
He said the two men shared an apartment close to where they were attacked and were childhood friends.
Olivares is a member of the criminal legislation committee and was working on a football-related violence initiative.
"I want to believe that it was a mistake. Olivares is an agricultural producer, a good man, a family man, we feel terrible," Julio Martínez, a senator in Olivares' home province of La Rioja, told Canal TN.