Some 32 children and one adult were burned alive on Sunday after the bus they were riding erupted in flames. Twenty-four other kids were injured. Charges of aggravated manslaughter will be slapped against the driver and church leader.

Accounts from witnesses showed the driver, identified as Jaime Gutierrez, left the small bus running while the children were on board when he got outside to refuel gas from a portable container, Luz Estella Duran, mayor of Fundacion village, told AP.

A spark ignited the fuel, according to prosecutors. The fire inferno spread easily to consume the bus and its passengers within seconds.

The bus carrying the children whose ages range from toddlers to 12 were returning home from Sunday school classes at a small Pentecostal church near the city of Fundacion, 750km (465 miles) north of the capital, Bogota.

One family is severely grieving because 13 of its children have been killed or injured in the blaze.

Merly Castro told Canal RCN news that five of their family members burned to death while six were hospitalized. Two others, who happen to be Merly's children, are missing.

"We couldn't do anything but hold our heads and watch the children burn," witness Jose Guette told AFP news agency.

Police also found Mr Gutierrez did not have a driving licence and that the bus had not passed the necessary technical inspection. It also lacked mandatory insurance.

Apart from Mr Gutierrez, church leader Manuel Salvador will likewise be slapped with manslaughter on 33 counts. Police discovered Mr Salvador was well aware of the lacking merits of the bus and the driver.

Initially fledding the scene of the accident, the driver turned himself in to police after local people bombarded his home with rocks.

Efforts continue to identify the victims who were burned beyond recognition. Two of the driver's children were among those killed.

The survivors meantime are battling horrific injuries in hospitals.

"The injured have second- and third-degree burns, and many are still in a critical condition," Cesar Uruena, working for the Red Cross, told AFP.

ATTENTION EDITORS - VISUALS COVERAGE OF SCENES OF DEATH AND INJURY Colombian policemen stand alongside recovered bodies of children who died in a burned bus in Fundacion, northern Colombia, May 18, 2014. As many as 26 people, most believed to be children
ATTENTION EDITORS - VISUALS COVERAGE OF SCENES OF DEATH AND INJURY Colombian policemen stand alongside recovered bodies of children who died in a burned bus in Fundacion, northern Colombia, May 18, 2014. As many as 26 people, most believed to be children, were killed and others injured in northern Colombia when fire broke out on a bus taking them to a church event, local media reported. REUTERS/Stringer REUTERS/Stringer
ATTENTION EDITORS - VISUAL COVERAGE OF SCENES OF INJURY OR DEATH The charred remains of a bus, in which children died in, is seen in Fundacion, northern Colombia, May 18, 2014. As many as 26 people, most believed to be children, were killed and others in
ATTENTION EDITORS - VISUAL COVERAGE OF SCENES OF INJURY OR DEATHThe charred remains of a bus, in which children died in, is seen in Fundacion, northern Colombia, May 18, 2014. As many as 26 people, most believed to be children, were killed and others injured in northern Colombia when fire broke out on a bus taking them to a church event, local media reported. REUTERS/Stringer REUTERS/Stringer
Relatives and residents light candles, in memory of the children who died in a burning bus, at the site of the accident in Fundacion, northern Colombia, May 19, 2014. Thirty-one children and one adult were killed in Colombia on Sunday when fuel exploded o
Relatives and residents light candles, in memory of the children who died in a burning bus, at the site of the accident in Fundacion, northern Colombia, May 19, 2014. Thirty-one children and one adult were killed in Colombia on Sunday when fuel exploded on a broken-down bus returning from a church event, an emergency response coordinator said. REUTERS/John Vizcaino REUTERS/John Vizcaino
A card, left in memory of the children who died in a burning bus, is seen at the site of the accident in Fundacion, northern Colombia, May 19, 2014. Thirty-one children and one adult were killed in Colombia on Sunday when fuel exploded on a broken-down bu
A card, left in memory of the children who died in a burning bus, is seen at the site of the accident in Fundacion, northern Colombia, May 19, 2014. Thirty-one children and one adult were killed in Colombia on Sunday when fuel exploded on a broken-down bus returning from a church event, an emergency response coordinator said. The card reads, "Let the children come to me, for theirs is the kingdom of heaven." REUTERS/John Vizcaino REUTERS/John Vizcaino
A relative places flowers at the site of a bus fire in Fundacion May 19, 2014. Thirty-one children and one adult were killed in Colombia on Sunday when fuel exploded on a broken-down bus returning from a church event, an emergency response coordinator sai
A relative places flowers at the site of a bus fire in Fundacion May 19, 2014. Thirty-one children and one adult were killed in Colombia on Sunday when fuel exploded on a broken-down bus returning from a church event, an emergency response coordinator said. REUTERS/John Vizcaino REUTERS/John Vizcaino