The blast occurred yesterday night during a Buddhist ceremony in Mandalay.
The monk, Ashin Wirathu, is accused of inciting violence with speeches warning that country's minority Muslim community poses a threat to Buddhist culture. He was unharmed.
A police officer who spoke anonymously because he was not authorized to speak to the media said today that the explosion went off under a parked car about 18 meters from the monk.
He said five people suffered minor injuries.
