There could be "severe humanitarian consequences" for children in Mali unless immediate steps are taken to guarantee their security, says World Vision.
"Children are especially vulnerable when military operations are launched, and this latest move has to be managed carefully and those who would like to flee have a safe passage out," says Chance Briggs, the head of World Vision's Mali office.
France began its military intervention in Mali on Friday in a bid to bring Islamist militants under control.
French fighters have launched air strikes on insurgent training camps, reportedly killing scores of rebels.
World Vision called upon governments involved in the northern offensive to take steps to ensure the safety of children and access for humanitarian organisations like World Vision.
"It would be intolerable to see more children separated from their parents, displaced from their homes, or cramped in refugee camps for weeks on end, not knowing where to go next or when they will be able to begin rebuilding their lives," said Briggs.
The Office of the United Nations High Commissioner for Refugees estimates that more than 400,000 people have fled their homes, and World Vision fears that the military offensive will displace thousands more.
Briggs added: "Last year was a particularly difficult year for children around the country, and the ongoing conflict in the north threatens them further. Their needs must be prioritised, and international humanitarian law abided by at every step."