CARACAS, Venezuela  —  Thousands of Venezuelans demonstrated nationwide Saturday as the government demanded the extradition of a Cuban exile accused of plotting the 1976 bombing of a Cuban jet that killed 73 people.

State-run television reported that thousands joined rallies at city plazas across the country to demand Washington turn over Luis Posada Carriles (search), now being held by U.S. immigration authorities. The state-run channel did not show images of demonstrations in other cities, and more precise crowd estimates were not available.

Hundreds of President Hugo Chavez's (search) supporters gathered in the historic Plaza Bolivar in Caracas, dancing to a band that sang one song urging the crowd to "fight against the protection of Luis Posada Carriles" by the United States.

"Legally, the United States must extradite Posada Carriles, a terrorist who committed crimes in Venezuela by planning the bombing here, then escaping from jail," said Carlos Bracamente, a 48-year-old shopkeeper.

Posada, who has denied wrongdoing, was being held without bond at a federal detention center in El Paso, Texas (search), while awaiting a hearing set for June 13.

Venezuela wants to try the 77-year-old, a staunch opponent of Cuba's Fidel Castro, with murder and treason for the bombing, which tore apart the Cubana Airlines plane after it took off from Barbados. Posada, an ex-CIA operative and a naturalized Venezuelan, is accused of plotting the attack in Caracas.

Two men who worked for Posada allegedly planted the bomb and were sentenced to 20-year prison terms. Posada was acquitted twice and escaped from a Venezuelan prison in 1985 while prosecutors were appealing.

U.S. authorities' decision days ago to charge Posada only with entering the country illegally has drawn sharp criticism from Chavez, who has accused the U.S. government of harboring a terrorist and trying to justify not turning him over.

"That man killed innocent people in his campaign against revolutionaries throughout Latin America for decades," said protester Manuel Montanez, 44. "I don't understand how those in Washington can say they fight terrorists, but they refuse to send one to face justice."

According to prosecutors, Posada escaped from prison twice. In 1982, disguised in a military uniform, he broke out by taking a prison guard hostage while brandishing a grenade and handgun, officials say. Posada and an accomplice were recaptured the next day.

In 1985, Posada escaped again. According to news reports at the time, officials said he paid prison officers a $28,600 bribe and walked out of the San Juan de los Morros prison. Some accounts said he was dressed as a priest.

Associates have said Posada then began working for the Iran-Contra project, helping the White House illegally ship arms to the Contra rebels in Central America. He was based in El Salvador's Ilopango Air Base and allegedly used the alias Ramon Medina.

Foreign Minister Ali Rodriguez said Washington must extradite Posada.

"The U.S. government is obliged to bring this man to Venezuela so the pending judicial process he faces in Venezuela is finished," said Rodriguez. His comments were echoed by the head of Venezuela's Supreme Court.

The decision by U.S. officials to charge Posada with only an immigration-related crime also has drawn criticism from 20 U.S. lawmakers, led by Rep. Dennis Kucinich of Ohio. The group of Democrats has sent President Bush a letter calling Posada a "terrorist" and saying he should be handed over to Venezuela.