At least two people have been injured after gunmen opened fire on a motorcade carrying Haiti's former president Jean-Bertrand Aristide.
The shooting took place at a busy junction in central Port-au-Prince on Monday.
Yvon Feuille, a senior executive of the Fanmi Lavalas political movement, said the attack was an "assassination attempt" carried out by people dressed as police officers.
Mr Aristide's US lawyer Ira Kurzban said the shots were apparently "fired by uniformed police directly at the vehicle in which President Aristide was a passenger."
He said at least two people standing in front of the vehicle were shot.
"Thank God no-one was killed and at least one of the shooting victims was taken to the university medical centre", he added.
Haitian National Police spokesman Garry Desrosiers said he did not have any information on the suspects.
The incident occurred after Mr Aristide appeared as a witness in a court hearing involving an associate - Jean Anthony Nazaire - who is facing a money laundering probe.
Aristide has not been in power for nearly 13 years and is a highly controversial figure in Haiti - extremely popular with some, but deeply reviled by others.