No one was injured in the explosion which happened close to a rarely-used gate of the official building.
"The bomb exploded outside the southern gate of the Bangabhaban (the presidential palace) just ten minutes after the president left the palace from another gate," a police officer told AFP, on condition of anonymity.
"The bomb was thrown from a moving vehicle. It was a small bomb and no one was injured," said another officer, also speaking on condition of anonymity.
Police were investigating the incident, he added.

Copyright AFP (Agence France-Presse), 2006