“The information we received from the boys in the car with him is that a car was trying to push them off the road, ramming them at every moment. So we think — we are convinced — that they wanted to harm them and ended up killing my father,” she said in a sound bite on Paya’s official website.

The Christian Liberation Movement, which was founded by Payá Sardiñas, is moreover calling on the Cuban military junta for a transparent investigation of the deaths.

In a statement Monday, the Movement said “the circumstances of these deaths have not been cleared up and are open to hypothesis’’ and demanded a “transparent’’ investigation.

Conflicting reports surround the events of Sunday afternoon on a highway in eastern Cuba as Payá, 60, who fought for human and civil rights in Cuba for more than two decades, and Cepero, who was the movement’s youth leader, traveled in a rental car with two Europeans who received minor injuries.

The two international supporters were identified as Ángel Carromero Barrios of Spain and Jens Aron Modig from Sweden. Spanish media reported that Carromero is a leader of the Spanish Popular Party’s youth organization Nuevas Generaciónes, and that Modig is president of the Swedish Christian Democrat Youth League.

According to the Cuban government, the rental car in which the four were travelling lost control and hit a tree at 1:50 pm local time Sunday in La Gavina, a town about 14 miles outside Bayamo, the capital city of Granma province.

In an unusual step, Granma, the official newspaper of the Communist Party of Cuba, reported the deaths Monday on page 6 and said the crash was under investigation.

The story called the incident “a regrettable traffic accident.’’ Although it mentioned the victims by name, it described them simply as “Cuban citizens.’’ The article also said that according to eyewitnesses, the vehicle went out of control and hit a tree.

The two injured men were treated at the Carlos Manuel de Céspedes clinic, the article said. Spanish news agency EFE, citing sources, said Carromero was the driver.

Ofelia Acevedo, Payá’s widow, said the Christian Liberation Movement “will continue its peaceful fight until all Cubans win the rights we have by law. My husband dedicated his life to this ideal until the end.

“From eternity,’’ she said, he will “encourage and accompany us until truth and justice make our dear island an authentic home for all Cubans.’’

Payá, who lived in Havana, was best known for his role in organizing the Varela Project, a signature gathering campaign in support of a referendum on laws to guarantee freedom of speech and other civil rights.

He won the European Parliament’s Sakharov Prize in 2002 and was nominated more than once for the Nobel Peace Prize.

Payá delivered the first group of more than 11,000 signatures to the National Assembly, Cuba’s parliament, in 2002. Before the petition drive was over, there were more than 25,000 names on the petition.

Many of the 75 dissidents who were jailed during the 2003 crackdown known as Cuba’s “Black Spring’’ were involved with the Varela Project, which took its name from Rev. Félix Varela, a priest revered for his role in Cuba’s independence fight against Spain.

Although authorities ignored the Varela Project petitions, the government did launch its own petition drive that established the socialist system as “irrevocable’’ in the Cuban constitution.

Nevertheless, Payá continued his efforts at trying to mobilize Cubans to demand their human rights. The same spirit guided him when he declared himself a candidate for the National Assembly in 1992 — the first time a dissident had publicly expressed a desire to run for such an office during the Castro regime.

“The unexpected and tragic death of this human rights activist is certainly a blow and a setback for Cuba’s small civil society; yet, his example and his courage will continue to inspire those both inside and outside of Cuba who work and struggle for a peaceful but real transition in Cuba to a democratic form of government in which both human rights and the rule of law are protected,’’ said Miami Archbishop Thomas Wenski in a statement.

“Oswaldo Payá was both a patriot and a committed Catholic layman: his vision for Cuba was founded as much in Catholic social teachings as in the thought of Felix Varela and Jose Marti,’’ said Wenski, who met Payá on several occasions.

A Mass in Payá’s honor was held last night at Ermita de la Caridad, known as the Shrine of Our Lady of Charity, in Coconut Grove. It was celebrated by Father José Luis Menendez, pastor of Corpus Christi Catholic Church in Miami.

Numerous dissidents gathered Monday at Payá’s home and at the Church of San Salvador in the Havana neighborhood of Cerro to pay tribute.

Several activists and dissidents were arrested at his funeral yesterday.

As word of Payá’s death spread, fellow dissidents and people from around the world eulogized him. Condolences poured in from the United States, Spain and the European Union.

Payá, the White House said, was a “tireless champion” in “the nonviolent struggle for freedom and democratic reform in Cuba.” 

“Cuba has lost one of its most important voices of political dissent and strongest proponents of fundamental freedoms for the people of his homeland. We extend our most heartfelt condolences to his wife, Ofelia Acevedo, and the entire family, which has lost a beloved husband and father,’’ said Victoria Nuland, a spokeswoman for the US State Department.

“Mr. Payá will be remembered for his vision and dedication to a better future for Cuba. His legacy will endure in the inspiration he provided to the Cuban people and his admirers the world over.”

Republican Florida Sen. Marco Rubio called Payá “one of many heroes on the island who has exposed the myths and failures of the Cuban Revolution and challenged its habitual violation of human rights.

“As we try to learn more about the circumstances of Payá’s death, it is critically important that the international community join those inside Cuba in pressuring the regime to be forthcoming with the truth,’’ he said in a statement. “We should insist that they be transparent in answering all the questions about Payá’s death. It’s important that anyone with knowledge about this car crash be protected and allowed to share what they know.”