Students masqueraded as rifle-toting federal agents, while others donned T-shirts with the face of a man they called Puerto Rico's ``liberator.''

Near the angry shouts and political placards stood Elma Beatriz Rosado with a calm explanation for it all: ``I want the FBI out of Puerto Rico. The time has come for them to leave, now.''

Rosado's husband -- convicted bank robber, fugitive and pro-independence activist Filiberto Ojeda Ríos -- was killed in an FBI shootout in September. In the months since, the FBI has catapulted onto the front pages here, accused of deliberately letting the founder of the radical Macheteros group bleed to death as well as stonewalling follow-up investigations.

Last month, federal agents executing search warrants on the homes of independentistas were captured on video pepper-spraying journalists covering the story, with seemingly little or no provocation, further fueling anti-FBI sentiment.

The Puerto Rico Department of Justice sued the FBI last week in federal court, saying the agency is obstructing local law enforcement investigations into the two incidents. Puerto Rico's Justice Secretary recently traveled to Washington to lobby Congress to pressure the FBI into releasing information about them.

Citing an ongoing investigation into Ojeda Ríos' death, the FBI officials declined to be interviewed for this article. In media releases, the FBI said it acted in good faith when facing an armed fugitive as well as reporters who were impeding an investigation by crossing a police line.

`VERY OFFENDED'

''People are very offended with what the FBI did,'' Puerto Rico Gov. Aníbal Acevedo Vilá told The Miami Herald. ''We have to recognize they have No. 1, made mistakes in those cases, and No. 2, they have not been open and communicative with the people of Puerto Rico to understand what happened'' in both incidents.

Now protests demanding the FBI's ouster are growing not just in frequency but also in participation. Thousands of Puerto Rican students, union activists, environmentalists and other sympathizers of liberal causes are joining the independentistas to rally against the FBI's presence on the island. When the international media convened at a San Juan baseball stadium for the World Baseball Classic earlier this month, they encountered demonstrators -- some wearing shirts bearing Ojeda Ríos' face -- stretched for a half mile across one of San Juan's biggest avenues.

VIEQUES CAMPAIGN

Some say the percolating distrust of the FBI and small but growing interest in ousting them could be the start of an important movement, like the one that eventually led the U.S. Navy to abandon its bombing range and other facilities on the nearby island of Vieques, east of Puerto Rico.

''I remember in 1979 when there were pickets against the U.S. Navy in Vieques, it was just us, the independentistas with our little picket signs,'' said attorney Wilma Reverón who is representing independence activists under investigation by the FBI. ``It took 20 years, but eventually everyone united. The struggle against the FBI will be long-term.''

The FBI has historically had a mixed image in Puerto Rico, a U.S. territory where a decades-old independence party garners some 5 percent of the popular vote. Over the years, some activists who consider the United States an imperialist colonizer have placed bombs, robbed banks and even shot their way into a U.S. president's home.

In one of the island's most notorious scandals, the FBI was accused of helping cover up the killings of two independence activists shot by Puerto Rican police in 1978. After a Puerto Rican Senate investigation five years later, Justice Department lawyers returned to San Juan and convicted 10 local officers of perjury or obstruction of justice.

During a 2000 House appropriations subcommittee hearing, then FBI Director Louis J. Freeh acknowledged that the FBI for decades kept secret files on dozens of members of the independence party. Freeh called it ``egregious illegal action, maybe criminal action, that occurred in the past.''

Created in 1956, the counterintelligence program was designed to investigate people viewed as threats to national security. At the time, Puerto Rico's independence movement was thriving; members had already shot their way into the Blair House where President Harry Truman was living. A White House guard and one of the Puerto Ricans was killed.

In the 1970s, Ojeda Ríos helped create los Macheteros -- Spanish for machete wielders -- an independence movement that advocated using violence against military targets. The group claimed responsibility for a 1979 bus ambush that killed two Navy technicians and wounded 10 other people and a 1981 attack that destroyed nine Puerto Rican Air National Guard planes.

In 1983, the Macheteros robbed a Wells Fargo bank in West Hartford, Conn., making off with $7.1 million. On the eve of his 1990 bank robbery trial, Ojeda Ríos vanished. He remained a fugitive until Sept. 23, when the FBI located and raided his Puerto Rico hideout, when they realized they had been detected. Ojeda Ríos opened fire on the agents, the FBI said, wounding one agent. Agents shot back, and waited to go inside until tactical agents from the States arrived the next day because they feared the house could be booby trapped, according to an FBI statement at the time.

FBI Director Robert Mueller asked the Justice Department's Inspector General's office to investigate the shooting.

''The death penalty is illegal in Puerto Rico,'' said Héctor Pesquera, a doctor who heads the Hostos National Independence Movement. Pesquera, who attended Ojeda Ríos' autopsy, said he bled to death after being shot in the shoulder.

Pesquera and other independence party members believe the FBI has launched a renewed campaign to discredit them at a time Congress is considering two bills that would address the future political status of Puerto Rico.

''This offensive is trying to criminalize the independence movement and to scare the United States and Congress of the possibility of becoming a state,'' he said. ``They want to portray Puerto Rico as a place full of terrorists.''

`POTENTIAL ATTACK'

On Feb. 10, the FBI executed six search warrants on independence movement leaders to prevent ''a potential domestic terrorist attack'' against ''privately owned interests in Puerto Rico,'' according to an FBI statement. Activists and politicians scoffed at the statement, because the governor and law enforcement authorities have said they were unaware of any such threats.

Puerto Rican politicians were infuriated when FBI agents were captured that day on video, showering reporters and photographers with pepper spray as the agents executed search warrants on activists' homes. The FBI defended the move, saying agents ''acted with restraint'' considering reporters had crossed a police perimeter.

Puerto Rico's justice secretary has said the FBI turned over weapons used on the Ojeda Ríos raid, but has not made agents available for interviews. In the pepper spray incident, the FBI has refused to identify the agent in the video, he said.