BRENTWOOD, N.Y. (AP) _ Dynamite or a pipe bomb exploded and started a fire today at the home of a former Latvian police officer who was cleared of charges that he helped Nazis murder Jews, authorities said.

Elmer Sprogis was home but was not injured, fire officials said.

FBI spokesman Joseph Valiquette said that shortly after the blast, a man called the Long Island-based newspaper Newsday, said he was from the Jewish Defense League and claimed responsibility for the blast.

There was no answer this morning to telephone calls seeking comment from the JDL in New York City.

Valiquette said investigators believed the blast was caused either by dynamite or a pipe bomb.

Assistant Brentwood Fire Chief John Pilger said neighbors reported hearing a blast at 4:20 a.m. When firefighters arrived, they found a man lying injured in the front section of the house.

He was taken to Southside Hospital and later transferred to University Hospital at Stony Brook, where hospital officials identified him as Robert Siegfield, 22. The extent of his injuries was not immediately known.

It was not known why he was at the house.

The fire caused minor damage to the house, officials said.

Sprogis came to the United States in 1951. The U.S. government tried unsuccessfully to strip him of his citizenship and deport him last year because of his alleged involvement in Nazi persecution during World War II.

A federal judge ruled the government failed to prove its case against Sprogis and dropped the charges. He said that although Sprogis may have been present when Jews were persecuted, there was no proof he participated.