At least 121 children were killed and 293 were injured in the first four months of the year, up 27% over the same period the previous year, according to figures released by UNICEF Thursday.
Roadside bombs and suicide attacks accounted for the largest number of casualties, 37%. The U.N. particularly criticized the Taliban's use of indiscriminate weapons triggered by victims stepping on or driving over a pressure plate, calling it a possible war crime.
Violence is increasing in Afghanistan as the Taliban and other militants press an intense offensive against government targets before international troops hand over full security responsibilities to Afghans. The international coalition is set to end its combat mission by the end of 2014.
The escalating attacks have caused civilian casualties to soar, including among children.
Last week alone, a suicide attack near a school in the eastern province of Paktia killed nine children and wounded seven others, and a father and three children died when their vehicle hit a roadside bomb.
On June 6, an airstrike by international military forces killed three children and injured seven in Kunar province.
UNICEF said that figures show 56% of child casualties were caused by insurgents and 14% caused by international and Afghan security forces. Another 30% showed no clear blame.
Meanwhile, six Afghan policemen were found shot at their checkpoint Thursday in the country's southern Musa Qala district in Helmand province. Two other policemen were missing, raising suspicions they killed their comrades, district chief Nayamatullah Samim said.
ALSO:Zimbabwe's Mugabe calls election but his rival rejects the date