Up to 6,000 children have been enrolled by warring militias in the Central African Republic, a senior UN official said Friday, issuing a stark warning about the country's spiralling humanitarian crisis. "Roughly today, we're talking about 5,000-6,000 children, so the number has roughly doubled from our previous estimate," made in March, said Souleymane Diabate, country representative in the CAR for the UN Children's Fund.