MIAMI, JUNE 14 -- A bomb exploded outside a Cuban museum in the "little Havana" neighborhood today, demolishing its facade and damaging part of an art show celebrating the 10th anniversary of the Mariel boatlift. No injuries were reported.

The blast, which left a small hole in the sidewalk outside the Cuban Museum of Art and Culture about 1 a.m., caused an estimated $10,000 to $20,000 in damage to two paintings and a sculpture included among works of 15 artists who arrived here in the refugee boatlift from Cuba.

Authorities also are still investigating a pipe-bomb explosion that damaged the museum in May 1988. The museum has been the focus of tension among Cuban exiles favoring or deploring dialogue with Cuba, which is governed by Fidel Castro.

The Federal Bureau of Investigation called today's incident an "act of terrorism" possibly fueled by political differences in the Cuban community, and linked the blast to 16 other improvised explosive devices found or exploded in Dade County since May 1987.

"The people believed responsible are people who . . . believed that the targets have advocated improving relationships with Cuba," FBI special agent Paul Miller said. No arrests have been made in any of the 17 bombing incidents, and Miller declined to elaborate on the investigation.