SAO PAULO (AP) -- At least one explosion Wednesday outside Brazil's Supreme Court killed a man and forced the justices and staff to evacuate the building in the capital of Brasilia, police and firefighters said.

A police statement said an artifact exploded outside the court without providing more details. Local firefighters later confirmed that one man died at the scene, but did not identify him.

The court's justices and staff safely left the building after the incident, which took place at about 7:30 p.m. local time, shortly after Wednesday's session finished.

Local media showed footage suggesting two blasts outside the court, with 20 seconds between the first and the second explosions.

The incident took place in Brasilia's Three Powers Plaza, an area where Brazil's main government buildings are located.

President Luiz Inácio Lula da Silva was not in the neighboring presidential palace at the time of the blasts, spokesman José Chrispiniano said.

Police blocked all access to the area where Brazil's Supreme Court, Congress and presidential palace are located. The presidential security bureau was conducting a sweep of the grounds around the presidential palace.

Brazil's federal police said it is investigating and did not provide a motive.

The Supreme Court in recent years has become a target for threats by far-right groups and supporters of former President Jair Bolsonaro due to its crackdown on the spread of false information. In particular, Justice Alexandre de Moraes has been a focus for their ire.

Earlier, another explosion was heard outside Brazil's Congress, but it apparently did not cause damages.