Police said gunfire erupted Friday as agents surrounded the farmhouse where Filiberto Ojeda Rios, 72, was hiding in the western town of Hormigueros and at least one agent was wounded.

A law enforcement agent who spoke on condition of anonymity and Hector Pesquera, president of the Hostiano independence movement, told The Associated Press Ojeda Rios was killed. But there was no official confirmation.

Main Puerto Rican radio and TV stations carried reports that Ojeda Rios, who had been in hiding for 15 years, was either captured or killed.

The robbery of $7.2 million from the Wells Fargo depot in West Hartford, Conn., constituted an act of domestic terrorism because it allegedly was carried out by 19 members of the Puerto Rican militant nationalist group Macheteros, or Cane Cutters.

Puerto Rico's police chief, Pedro Toledo, told Radio WKAQ that FBI agents had arrested Ojeda Rios' wife. He confirmed that an FBI agent was wounded in the gunbattle and taken to a hospital.

FBI spokesman Louis Feliciano confirmed a "tactical operation" in the area but declined to elaborate. Law enforcement agents said the operation also involved U.S. Marshals, Puerto Rican police and Puerto Rican prosecutors.

They were reluctant to go on the record about the operation because of the sensitive issue of independence and sovereignty in a U.S. territory. Some 500 people protested the move against Ojeda Rios late Friday, blocking a main avenue in the capital San Juan.

"This was done on purpose ... to try to humiliate us," Jorge Farinacci, president of the Socialist Front, said at the demonstration. "It's to tell us 'You do not have the right to independence.'"

A second law enforcement agent who also spoke on condition of anonymity said four Puerto Rican prosecutors arrived at the scene late Friday, and said this indicated someone had been killed and their presence was needed to remove the body.

Ojeda Rios, leader of the Macheteros, is one of four men still wanted for the Wells Fargo robbery. He was released on bail in 1988 after about three years in prison awaiting trial in Connecticut. In 1990, he cut off an electronic monitoring bracelet and went into hiding.

He was convicted in absentia in 1992 on charges of robbery, conspiracy and transportation of stolen money and was sentenced to 55 years in prison.

Only about $80,000 of the $7.2 million has been recovered. The federal government believes most was used in Puerto Rico to finance the independence movement.

The United States seized Puerto Rico in the Spanish-American War. Puerto Ricans are U.S. citizens but cannot vote for U.S. president, have no voting representation in Congress and pay no federal taxes.

Most Puerto Ricans are split between those who support making the island a U.S. state and those who favor keeping its status as a U.S. commonwealth. A small but vocal minority supports independence.