By Hilda Inclan

A Miami-based, anti-Castro terrorist group is claiming responsibility for the bombing of the Cuban consulate in Madrid Tuesday.

The claim was made by the mysterious "Ignacio," who says he speaks for the National Cuban Liberation Front (FLNC). The group recently boasted of bombing Cuban consulates in Mexico and Jamaica.

The Madrid bombing is the FLNC's answer to a federal investigation of its activities, now in its secnd week here, Ignacio indicated.

"Nothing that the U.S. government may be trying to do to stop us will have any effect, except to make us work harder and faster," Ignacio said.

Police and consulate sources said the Cuban consulate was rocked Tuesday by a bomb that destroyed three floors of the six-story building in which the consulate is housed. No injuries were reported. The Spanish government has already expressed its regrets over the matter to the Cuban government in Havana.

Madrid police sources said an investigation is under way. Ignacio told the Miami News the blast was part of the FLNC strategy of "hitting Castro whenever and where ever we can" and of "internationalizing the war against the Cuban Communist regime."

A federal Justice Department and Grand Jury investigation into the FLNC began in Miami after the March 20 Little Havana explosion in which two Cubans police said were FLNC members were wounded when a bomb they were making blew up in their hands.