Families in Ecuador on Saturday were mourning victims of a Christmas Eve road accident, in which a bus plunged into a steep ravine, killing at least 41, including seven children.
Rescue officials said around 30 passengers had survived, but had been injured, some of them badly.
"There's been a very serious accident with approximately 41 people killed," National Transport Council (CNT) director Ricardo Anton told reporters.
Earlier reports put the death toll at 35.
Fernando Gandarillas, a spokesman for the Ecuadoran Red Cross, told AFP the bus had fallen into a ravine as it negotiated a descent.
It was travelling Friday from the capital Quito to the eastern towns of Chone and San Isidro, a trip of more than 250 kilometers (180 miles), he said.
A police chief from a nearby town of El Carmen, Diego Iniguez, told journalists the bus had been filled over capacity and appeared to have experienced a gearbox problem before the driver lost control.
President Rafael Correa denounced "the irresponsibility of the driver who crashed with more than 70 passengers" on board.
"He picked up passengers along the road, which is prohibited," Correa told a Christmas meeting with his staff.
"It's a well-designed highway," he added.
One survivor told television station Ecuavisa that just before the accident a woman at the front of the bus had started screaming that the driver could not shift gears.
He said the driver appeared to attempt to keep control of the vehicle, but failed and the bus rolled over for some 200 meters (yards) before hitting a tree then dropping into the ravine.
Another survivor, Juan Pablo Alcivar, told Radio Quito how the bus's gears were heard grinding as the driver tried to downshift.
The police traffic accident service said it was at the scene of the carnage to try to determine what went wrong.
The injured were taken to several hospitals in the area, while the bodies were piled up inside police vans and delivered to morgues.
The bus belonged to the east Ecuadoran coach company Reina del Camino. CNT director Anton said its operations had been suspended.
"There was a terrible mistake made in this accident," Anton told reporters.
He was asking police for "the reason the bus was allowed to leave with too many passengers," he added.
The accident occurred on a busy day on the South American nation's roads, as thousands of Ecuadorans streamed back to home towns to share in family Christmas gatherings.
The country has a poor road safety record, and Ecuadorans are known for their aggressive driving habits.
Attorney General Washington Pesantez said there was a traffic death on average every three hours, generating 500 million dollars in costs to society every year.
In August a coach fell into a 100-meter (330-foot) ravine in southern Ecuador, killing 38 people and injuring 12.
Road accidents were the second-biggest cause of death in the country of 13 million people.
The government, which has been running a driver awareness campaign, says 3,000 fatalities were recorded this year to November, in 43,000 reported accidents.