Washington, Apr 14 (IANS): A dozen US Secret Service agents assigned to Colombia's Cartagena port city ahead of President Barack Obama's arrival for an Americas summit were sent home for alleged misconduct that involved prostitutes, officials said.

The 12 agents were replaced Friday by other US Secret Service personnel so that Obama's security plan would not be affected, Xinhua reported citing MSNBC.

Those involved in the allegations were relieved of duty and sent back home.

The matter was being handled by the Secret Service's Office of Professional Responsibility.

Obama is in Cartagena for the sixth Summit of the Americas, which is to be held over the weekend.

The misconduct reportedly occurred before Obama arrived Friday for the meeting of more than 30 world leaders that begins Saturday.

According to the New York Times, Secret Service spokesman Edwin M. Donovan acknowledged that some agents had been recalled because of accusations of misconduct and that they would be replaced by other Secret Service personnel. But he did not address the issue of prostitution.

Prostitution is legal in designated areas of Colombia, the daily said.

Jon Adler, president of the Federal Law Enforcement Officers Association, told the Washington Post that the accusations were related to at least one agent being involved with prostitutes in Cartagena.

He said the entire unit was recalled for investigation.