Once again, Miami is sizzling with spy fever.

One day after the FBI unmasked an alleged Cuban spy network in South Florida, Cuban Miami began looking for more spies with a pipeline to Fidel Castro.

On local Cuban radio, commentator Ninoska Perez-Castellon gave the phone number to the FBI switchboard and asked listeners to report suspicious characters. When she opened WQBA-1140 AM's phone lines, there was no shortage of spy catchers.

``Let them shake down every place because there are many, many spies here,'' said a caller who identified herself as Julia of Miami.

``We know we are surrounded by them,'' said Armando, another a caller.

Armando then rattled off his list of suspects: people in the travel-to-Cuba business and exiles who advocate rapprochement with Cuba. He said he would be ``able to die in peace'' if they were arrested and charged.

Spy fever broke out late Monday, when the FBI charged 10 Cubans with trying to infiltrate exile groups and U.S. military bases and with planting information to discredit exiles and foment disharmony in South Florida.

At the press conference announcing the arrests, FBI special-agent-in-charge Hector Pesquera said the bureau decided to go public with the spy arrests, hoping people with more information would come forward.

``We have done this publicly to gather information from the public,'' Pesquera said in Spanish. His message was broadcast several times over Cuban radio.

If the phones at headquarters were ringing steadily Wednesday, the FBI wouldn't say.

``I can tell you yes, we are receiving calls on illegal activities and we are always happy to sift through those,'' FBI spokesman Mike Fabregas said Tuesday. ``That's what that line is for. But part of our guarantee [to people who call] is we don't give our information out.''

Cuba and exile watchers weren't surprised at the spy buzz. In Miami, the discovery of yet another exile caper routinely generates a rush of spy-watching.

After the 1996 shoot-down of two Brothers to the Rescue planes by Cuban MiGs, it was discovered that a Brothers pilot, Juan Pablo Roque, was actually snitching for the Cuban government. When his story became public, exile organizations admitted that they knew they were infiltrated with Castro agents. At the time, they predicted that more spies would be found.

``All exile leaders know there are Cuban agents working in Miami,'' said Jaime Suchlicki, a University of Miami professor of international relations. ``What is new is that the FBI arrested them and held this press conference.''

The arrests are ``going to make Cuban-exile organizations a little more paranoid about spies -- and they should be paranoid because there are spies,'' Suchlicki said. ``This all could create new mistrust among exiles.''

Some exile groups are already at work on a strategy to deal with the spy arrests.

Public hearing sought

The Cuban American National Foundation, the largest and most powerful of exile groups, sent a letter Tuesday to U.S. Sen. Bob Graham, a member of the Senate's intelligence committee, asking him to conduct a public hearing in Miami on Cuban espionage.

``Our community has been concerned for years by the presence of Castro's intelligence agents here in Miami,'' said the letter signed by CANF Chairman Alberto Hernandez and Vice Chairman Jorge Mas. The espionage ``has not only caused great harm to our community in disseminating disinformation and sowing discord, but which we now see has been threatening vital security interests of the United States.''

The CANF letter included a list of activities the organization has been gathering on Cuba's covert activities -- including ``the sophisticated electronic espionage facility in Lourdes, Cuba . . . used to collect personal information about U.S. citizens in the private and government sectors.''

Ramon Saul Sanchez, head of the Democracia Movement, said his group always has done background checks on people in its leadership ranks. But one of the alleged spies arrested Monday, who held the post of assistant director of air command in the movement, was not detected through that process, Sanchez said.

``We are going to double our security efforts,'' Sanchez said, ``but it's very difficult to tell who is a spy. Even the intelligence agencies are penetrated, let alone a group like ours.''

Comments called `slanderous'

People in the travel-to-Cuba business, who are often criticized by hard-line commentators, were angry that their names were being singled out on Cuban radio.

``Ignorant comments such as those are not only slanderous, but paranoid and not worthy of being responded to,'' said Vivian Mannerud, who has owned the Miami-to-Cuba air charter company ABC Charters for the past 16 years.

Federal authorities have acknowledged for years that agents of the Cuban government are living in South Florida, gathering information and infiltrating exile groups. But until Monday, they had never made any significant arrests.

``This proves that what we have been saying for years is not a figment of our imagination,'' said Silvia Iriondo of the group Mothers Against Repression. ``It's about time the federal authorities did something about this.''

Herald staff writer Cynthia Corzo contributed to this report.