Police said two suicide bombers opened fire and tossed a hand grenade inside the courtroom of Additional Session Judge Rafaqat Awan, the Pakistan Tribune reported.
The Associated Press of Pakistan said the attackers, estimated to be about 15 years old, opened fire and threw hand grenades into different courtrooms and other rooms.
When police tried to overpower them, the suicide bombers detonated their body explosives, officials said.
At least 29 people were injured in the attack, medical personnel said.
Swim Week Miami Beach 2014 [PHOTOS]