HAVANA (Reuters) - Cuba has foiled a plot to sneak arms and ammunition onto the Caribbean island from the United States, detaining nearly three dozen people in a broader scheme authorities say sought to destabilize its government, a Cuba Interior Ministry official said on Monday.

Cuba first unveiled details of the plot last December, when authorities said a Cuban man residing in the United States arrived on the island by jetski, armed with guns, ammunition and military gear, to recruit others and commit acts of violence.

A subsequent seven-month investigation, said Víctor Álvarez, a lead criminal investigator with Cuba's Interior Ministry, unveiled a broader plan that includes participation by 32 Cuban residents and a U.S.-based group called La Nueva Nación Cubana, which Cuban authorities say continues to plot attacks on Cuba from U.S. soil.

Cuba said it had notified the U.S. government agencies of the results of the investigation, but said the individuals continue to act with impunity.

"These individuals continue to act with impunity in North American territory, organizing, financing and supporting activities of a violent nature in order to subvert the internal order of our country," Alvarez said.

The U.S. State Department said it was aware of the most recent allegations.

"U.S. law enforcement prosecutes individuals based on U.S. law and does not take direction from foreign governments," a state department official told Reuters on Monday via email.

Cuban authorities provided Reuters with what they said was a videotaped confession from Ardenys García, who allegedly entered Cuba by jetski in November before proceeding to recruit others to join him.

Officials said Garcia, who is now detained in Cuba, also faces human trafficking charges in the United States.

Cuba has for decades alleged the United States turns a blind eye to plots hatched by Cuban nationals residing in the United States to foment unrest on the island and upend its government.

Cuba in December published a list of foreign nationals and entities - including La Nueva Nación Cubana - that it accuses of involvement with terrorism, including many long-time dissidents who reside in the United States.

The list includes dozens of people Cuba says have been implicated in hotel bombings, plots to foment unrest, and assassination attempts against Fidel Castro, many of which date back decades.

The Cuban list appears to be the island`s response to a U.S. decision to keep Cuba on its own list of state sponsors of terrorism, a designation that subjects Cuba to harsh sanctions and considerable economic hardship.

(Reporting by Nelson Acosta, Editing by Dave Sherwood and Aurora Ellis)

By Nelson Acosta