The Cuban Council of Churches says 20 priests from an evangelical church are among the dead in the Havana plane crash on Friday.
"On that plane were 10 couples of pastors. 20 people. All of the Nazarene Church in the eastern region," confirmed Maite Quesada, a member of the council.
The group spent several days at a meeting in the capital and were returning to their homes and places of worship in the province of Holguin.
The plane, a 39-year-old airliner with 110 people aboard, crashed and burned in a cassava field just after taking off from the Havana airport Friday, leaving three survivors in Cuba's worst aviation disaster in three decades, officials said.
The Boeing 737 went down just after noon a short distance from the end of the runway at Jose Marti International Airport while on a short-hop flight to the eastern city of Holguin. Firefighters rushed to extinguish the flames that engulfed the field of debris left where Cubana Flight 972 hit the ground.
"There is a high number of people who appear to have died," Cuban President Miguel Diaz-Canel said from the scene. "Things have been organized, the fire has been put out, and the remains are being identified."
Relatives of those aboard were ushered into a private area at the terminal to await word on their loved ones.
"My daughter is 24, my God, she's only 24!" cried Beatriz Pantoja, whose daughter Leticia was on the plane.
State TV said the jet veered sharply to the right after takeoff, and Diaz-Canel said a special commission had been formed to investigate the cause of the crash.
"The only thing we heard, when we were checking in, an explosion, the lights went out in the airport and we looked out and saw black smoke rising and they told us a plane had crashed," Argentine tourist Brian Horanbuena told The Associated Press at the airport.
Skies were overcast and rainy at the airport at the time of the incident, with winds reportedly around 4 mph (6 kph).
Authorities said there were 104 passengers and six crew members on the flight operated by the Cuban state airline. Cuban media reported that five children were among those on board the plane.
Mexican authorities said the Boeing 737-201 was built in 1979 and rented by Cubana from Aerolineas Damojh, a small charter company that also goes by the name Global Air.
A statement from the country's Transportation Department identified the pilot and co-pilot as Capt. Jorge Luis Nunez Santos and first officer Miguel Angel Arreola Ramirez. It said the flight attendants were Maria Daniela Rios, Abigail Hernandez Garcia and Beatriz Limon. Global Air said maintenance worker Marco Antonio Lopez Perez was also aboard.
Outside the company's Mexico City offices, former Global Air flight attendant Ana Marlen Covarrubias said she had worked for the company for over seven years and knows nearly all the crew members.
"I don't have the words. I'm very sad. We're in mourning," a she said in tears. "It was something really, really, really terrible; a tragedy for us."
In addition to the Mexican crew, Cuban Communist Party newspaper Granma reported that the passengers were mostly Cubans plus five foreigners from countries it did not identify. Argentina's Foreign Ministry said two of its citizens had died in the crash.
In November 2010 a Global Air flight originating in Mexico City made an emergency landing in Puerto Vallarta because its front landing gear did not deploy. The fire was quickly extinguished, and none of the 104 people aboard were injured. That plane was a 737 first put into service in 1975.
Cubana has had a generally good safety record but is notorious for delays and cancellations and has taken many of its planes out of service because of maintenance problems in recent months, prompting it to hire charter aircraft from other companies.
Four crash survivors were taken to a Havana hospital, and three remained alive as of mid-afternoon, hospital director Martinez Blanco told Cuban state TV.
State media reports stopped short of openly declaring the rest on board were dead, but there was no word of other survivors by Friday evening.
Cuban First Vice President Salvador Valdes Mesa had met with Cubana officials on Thursday to discuss improvements to its service. The airline blames its spotty record on a lack of parts and airplanes because of the U.S. trade embargo against the communist-run country.
It was Cuba's third major aviation accident since 2010.
Last year a Cuban military plane crashed into a hillside in the western province of Artemisa, killing eight soldiers. In 2010, an AeroCaribbean flight from Santiago to Havana went down in bad weather, killing all 68 people aboard, including 28 foreigners, in what was the country's worst air disaster in more than two decades.
The last deadly accident involving a Cubana-operated plane was in 1989, when a charter flight from Havana to Milan, Italy, crashed shortly after takeoff, killing all 126 people on board and at least two dozen on the ground.
Cubana's director general, Capt. Hermes Hernandez Dumas, told state media last month that the airline's domestic flights had carried 11,700 more passengers than planned between January and April.
He said 64 percent of flights took off on time, up from 59 percent the previous year.
Associated Press writer Amy Guthrie contributed to this report.