Man dead after suspected failed attack on Brazil Supreme Court ahead of G20

LONDON -- A man killed by explosions outside of Brazil's Supreme Court in Brasilia on Wednesday night is suspected to have been trying to launch an attack, a presidential official said, as authorities investigate the incident just days ahead of the G20 meeting in Rio de Janeiro.

In a statement, the court said two "loud bangs" were heard Wednesday evening prompting ministers and staff to be evacuated from the area. The incident occurred at the end of the court's Wednesday session.

The presidential office official said the suspect was named as Francisco Wanderley Luiz. The man was seen leaving his car carrying a small bag at around 7:30 p.m. local time.

The official said Luiz tried to gain access to the Supreme Court building but failed to do so. Luiz then detonated the device he was carrying, killing himself.

Military police told ABC News that explosives and a timer were found on the dead man's body. They said the first explosion went off in a street next to the Congress building. The second explosion -- which killed the suspect -- went off at the entrance of the Supreme Court building, military police said.

The prosecutor's office said the incident is being investigated as a terror attack and that the suspect is believed to have been acting alone as a "lone wolf."

ABC News' Will Gretsky and Aicha El Hammar Castano contributed to this report.