By BARBARA GUTIERREZ

Jose Marquez, owner of El Titan Market, was baffled by Wednesday morning's firebombing of his small store, and even more puzzled that a caller who claimed Omega 7 was responsible for fire attack accused him of being a Communist.

"I fled Cuba in a small boat 21 years ago," said Marquez, 68, standing in the middle of his store at 336 NW 12th Ave. "I don't belong to any political associations. I cannot be a Communist!"

The explosion set the tar and stone roof of the small bodega ablaze at 5:20 a.m., but the fire only charred it, said Miami police spokesman Mike Stewart. No one was injured.

Less than 10 minutes after the explosion, a man called Spanish-language radio station WRHC and said that Omega 7 was "claiming responsibility for the explosion," Stewart said.

The caller said that the "owners of the store were Communist," said Tomas Regalado, WRHC news director.

On the roof, police found two Molotov cocktails, two homemade explosive devices and two empty gasoline cans, Stewart said.

The firebombing comes at a time when Eduardo Arocena, the alleged leader of Omega 7, has been charged with transporting explosives from state to state. The FBI, which brought the charges against Arocena, has joined Miami police in investigating the firebombing, said Dennis Erich, an FBI spokesman.

"All we can say is that we are investigating along with the local authorities," said Erich. "As far as Arocena's association with this, we have no comment."

Since 1976, Omega 7 has claimed responsibility for more than 30 bombings and two murders. In January, Omega 7 claimed responsibility for bombing three Little Havana businesses - Replica magazine, Padron Cigar Factory and Paradise International Inc., an agency that books exile trips to Cuba. No one was injured in those bombings.

But the attack on El Titan, a market that caters mostly to elderly Latins, left a lot of questions unanswered. Shoppers walked in and out of the store as usual Wednesday afternoon.

"I know these people the two years they've been here," said Fidel Santamaria, 67, a customer at the store. "They are not Communists, but they are good businessmen. Maybe someone did this to them because they were jealous."

Marquez's son Joaquin, who is co-owner of the store, said that he and his father bought El Titan two years ago and have tried to attract customers by offering baked Cuban bread and pork.

"We work hard here and try to provide good products to the community. We are not involved in politics," he said. "This bombing was a complete surprise. If indeed it was Omega 7, then it was a mistake."