Federal prosecutors in Miami have doubled the size of their corruption unit to try to root out problems in the city's government, the Miami Herald reported Saturday.

The paper said investigators were focusing on the Port of Miami and Miami International Airport, looking for evidence of shakedowns and influence-peddling by city officials."At the port and at the airport, we've expanded our investigative efforts in a lot of different areas," U.S. Attorney Thomas Scott told the newspaper. "From a public corruption standpoint, they are on our radar screen."

Ten Miami-Dade county detectives have been lent to the Federal Bureau of Investigation to assist in the probe, the paper said.

Miami's image has suffered recently from reports of election fraud, bribery and other official corruption.