A six-stick dynamite bomb blew up the office of a Cuban unity group early today as hundreds of exiles walked off their jobs protesting the jailing of their emerging leader, Felipe Rivero.

Miami police and sheriff's deputies trotted out billy clubs and riot equipment and patrolled the southwest section known as "Little Havana." Hundreds of exiles jammed street corners along the Tamiami Trail.

The bombing of the Flagler Street headquarters of the Cuban Exile Representation and walkouts at severald factories, breweries and boatyards were intended to put pressure on the U.S. to release Rivero.

Rivero, arrested May 12, is held in Ward D. of Jackson Memorial Hospital. He is charged with threatening the blow up the Cuban pavilion at Expo 67.

There were no injuries in the 2:30 a.m. bombing that wrecked the arcade building at 1784 Flagler and sprayed glass across the broad but then empty street.

Four men, apparently Cubans, were seen fleeing the spot in a white Cadillac moments before the explosion.

Miami police loaded a huge paddy wagon with riot and tear gas guns and motorcycle men were issued three-foot-long clubs.

Capt. Roy Longbottom of the Dade Public Safety Department said, "We're ready and watching."

Many Cuban businessmen, he said, had been busy all morning in an attempt to cool the hotheads who wanted violence.

The walkout was spotty.

At Berram Yacht Company, about 175 workers did not show up for work. But at the Columbus and Everglades hotels, there were no job defectors.

Dade schools reported that of 20500 Cuban children, some 3000 chose to play mass hooky.

Cover girl of Miami, a dress making firm, said about 60 girls failed to show, and Alix of Miami, another garment firm, reported about 40% of its workers stayed away.

Mr. Dino, a woman's apparel company, said all of its workers - 300 - took a holiday.

At about 11 a.m., police assembled in a Lummus Park "staging area" and were ordered to more toward Bayfront Park.

Bayfront is the favorite demonstration area of Miami's Cuban colony and it was there that police feared real trouble might develop.

A report that hundreds of Cuban teens were already marching on the Torch of Friendship was discounted when only a handful showed up. Last week refugees doused the gas light that burns eternally, and some burned letters they'd received from Immigration authorities.

First to go on strike were about 200 exiles employed at the Thunderbird Boat Company. Then the two breweries, Regal and Tres Caballos, were struck.

Miami police roving the near-southwest section said street corners were mobbed by Cubans who were "polite enough but would go away and then assemble all over again."

A mass protest demonstration against Rivero's imprisonment was threatened for later in the day.

The strike took on national importance as Cubans in New York, New Jersey, and California said they would leave their jobs.

Mayor Robert King High in New York on City Business said by phone that "those who have done these acts have done harm to many thousands of Cubans who have become good citizens of Miami and the United States.

"This city nor any city in the United States simply will not abide violence as a substitute for the orderly procedure of law."

High said Cubans angered over Rivero's jailing should take their case to the courts.

At Caressa, Inc., a shoe manufacturer at 3601 NW 54^th Street, hiaaleah, reported 300 workers milled around a drizzle outside the plant refusing to work.

On the other hand, Joseph Milton, executive vice-president of Propeller Service of Miami, Inc., at Miami international airport, reported the 100 Cuban workers there decided to hold a token strike.

"They met last night, and decided that due to the fact that we have military contracts and the government needs our stuff, they'd just have two men take off as a token," he said.

"They asked me to say that their sentiments are all for Rivero, but they realize the gravity of the government's needs."

Business places throughout the Cuban section blossomed with signs saying, "Deportation No, The Right to Fight, Yes," and "We Demand Freedom for Felipe Rivero."

Rivero will get a deportation hearing May 29.

Robert L. Woytyeh, district director of the Immigration Service for Miami, said he didn’t see much chance of Rivero's winning immediate freedom.

"I've received no orders to free Rivero," Woytyeh said.

Said a pal of Rivero's, "He is a fighter and they are tying his hands because he is striking a blow for freedom."

Rivero has been a proponent of the so-called "third position." It is neither pro-Russian nor pro-American.

Rivero calls it "pro-Cuban."

Rivero was captured at the Bay of Pigs invasion and later pretended Castro agents had been successful in brainwashing him.

Then, when Fidel exhibited him on television, Felipe suddenly loosened a blast against Communism and Castro. The tirade was heard across Cuba.

Rivero was freed in the ransoming of 1962 and since has been using Miami as his base for revolutionary activities.

He is currently the big man among the city's 100,000-plus Cuban refugees.