An Ecuadorian court on Monday sentenced 11 of 17 soldiers to more than 34 years in prison over the forced disappearance of four boys aged 11 to 15 during security operations in the South American nation's largest city, Guayaquil, one year ago.

This was the sentence sought by prosecutors against the 11 soldiers who were accused of directly perpetrating the crime.

The court also sentenced five soldiers who collaborated with the prosecution over the case to two and a half years behind bars. A lieutenant colonel accused of being complicit but who was not part of the patrol was declared innocent.

The children went missing in December last year in Guayaquil's Las Malvinas neighbourhood during a military offensive against organised crime launched by President Daniel Noboa, who has decreed various states of emergency and ordered soldiers to patrol the streets.

Soldiers allegedly detained the children during a night patrol, after which they beat them, forced them to take off their clothes and abandoned them naked in Taura, a dangerous rural community some 30 km (19 miles) south of the city.

One of the children called his father from Taura, but when he arrived to pick them up he could not find them, according to witness testimonies. Days later, authorities said they had identified four charred bodies found in Taura as the missing children.

"The patrol abandoned the minors in that area, knowing it was dangerous, desolate, and abandoned," Judge Jovanny Suarez said in the ruling that ended a weeks-long criminal trial.

The soldiers' lawyers had argued the prosecutors' evidence was not conclusive, that the soldiers were sent on patrol without prior training and that they had left the minors alive in Taura.

Defense Minister Gian Carlo Loffredo said at the start of the investigation that the children had been detained over their alleged involvement in a robbery.

The boys' family members said they had left home to play soccer on the day they disappeared. Their lawyers said autopsies found injuries and bruises sustained prior to their deaths.

Prosecutors said earlier this month they are also seeking convictions against six other soldiers in a separate case, over an alleged extrajudicial execution during an anti-drug operation in Ecuador's coastal province of Santa Elena.