At least 10 female farm workers, nine of them children, died in Egypt on Tuesday when a minibus plunged off a river ferry and into the Nile northwest of Cairo, the health ministry said.
"The toll is at 10 and could rise," ministry spokesman Hossam Abdelghaffar told AFP.
Reporting the accident, the state's flagship Al-Ahram newspaper said the driver, who had released the handbrake, was arrested while trying to flee.
He had "a verbal argument" with one of the passengers before getting out of the bus, the paper said.
Two of the victims - all of whom worked on an "export-oriented fruit farm" - were 13 years old, according to a list published by Al-Ahram.
The rest were 16 and younger, except for one victim who was identified as a 40-year-old woman.
The vehicle sank at the village of Abu Ghalib, some 50 kilometres northwest of the capital.
Villagers used small wooden boats to row out and help search-and-rescue workers look for survivors, as relatives waited anxiously on the banks of the narrow stretch of the Nile.
A crane was finally able to lift the minibus from the water, after rescuers and locals had swum out to extract victims from the windows of the submerged vehicle.
Nine injured passengers - most of them also minors, according to al-Ahram's list - were taken to nearby hospitals for treatment, the health ministry said in a statement.
A search operation was "ongoing" into the evening for five more passengers who were unaccounted for, Al-Ahram said.
The Ministry of Social Solidarity said it would provide financial compensation "to the families of the deceased and injured".
After carrying out an initial investigation at the scene, the public prosecutor's office ordered a technical inspection of the minibus to try to determine "the reasons it had plunged into the water", Al-Ahram reported.
Commuter accidents are common in Egypt, especially in agricultural areas along the Nile and adjoining streams, where small, overloaded boats ferry farmers and workers back and forth.
At least 1.3 million children are engaged in some form of child labour in the Arab world's most populous nation, official figures show.
Most do unpaid work on family farms, according to the International Labour Organization.
However, children are also frequently sent to work on large-scale export-oriented farms, according to rural sociologist Saker al-Nour, who has studied agricultural labour conditions extensively.
"These accidents happen repeatedly because girls are packed, in their own words, like sardines into these minibuses" to go and work in "terrible conditions", he told AFP.