A man killed himself while detonating explosives after trying to enter Brazil’s Supreme Court, authorities said Wednesday, in an attack on the political heart of the country that prompted the evacuation of court staff and legislators in the capital Brasilia.

Two powerful explosions occurred at Brazil's supreme court around 7:30 p.m., shortly after the day's session concluded.

The authorities were treating the blasts in Brasília, the capital, as the work of a lone bomber, who was believed to have been the person killed.