A bomb has exploded at Indonesia's parliament, police have said.
The blast caused no casualties
The blast damaged the building but caused no casualties, police said. Parliament is in recess.
Few other details were available and no group has admitted planting the device so far.
The blast, which occurred at about 0700 (midnight GMT), is the latest in a series of small bombings in the country since an attack on the resort island of Bali last year left more than 200 dead.
"It was a bomb," a senior police officer who declined to be named told the Associated Press.
The explosion comes after police last week arrested at least seven suspected Jemaah Islamiah militants.
Police also found large amounts of ammunition and enough chemicals and explosives for several Bali-style attacks.
They also seized a possible list of targets, the BBC's Tim Johnston in Indonesia reports.
He says that if Monday's bombing is found to have been carried out by extremists, it will prove just how deep they can penetrate.