KABUL, Afghanistan -- The number of children killed and wounded in Afghanistan's war jumped by 34 per cent last year as the Taliban stepped up attacks across the country and continued to lay thousands of roadside bombs, the United Nations said Saturday.

Overall civilian casualties were up by 14 per cent, reversing 2012's downward trend and making 2013 one of the deadliest years of the 12-year war for civilians, the UN Assistance Mission for Afghanistan said in a report.

The rising civilian toll underscores mounting levels of violence in Afghanistan. Taliban insurgents have ramped up attacks to try to gain ground and shake the Afghan government's confidence as international combat troops prepare to complete their withdrawal at the end of the year.

The UN report also noted an "alarming" new trend for 2013 -- the increasing numbers of civilians being harmed in fighting between the Taliban and Afghan security forces.

It recorded a total of 962 battles in which civilians were harmed last year -- an average rate of nearly 20 such battles every week -- and said civilian casualties caused by such fighting rose by 43 per cent over the previous year.

In terms of deaths and injuries, 2013 was also the worst year of the war for Afghan women and children, with most of the casualties caused by either stepping on or driving over roadside bombs or getting caught in fighting.

"It is the awful reality that most women and children were killed and injured in their daily lives -- at home, on their way to school, working in the fields or travelling to a social event," said Georgette Gagnon, director of human rights for the UN mission, calling on all sides to work to protect civilians from harm.

UNAMA said 561 children were killed and 1,195 were wounded in 2013, a rise of 34 per cent in the combined number of casualties. Also last year, 235 women died and 511 were wounded, a rise of 36 per cent in combined casualties. The breakdown for deaths and injuries for children in 2012 was not available.

On Saturday, another child was killed when a roadside bomb detonated near a high school in the city of Jalalabad. Eight other people were wounded, said Ahmad Zia Abdulzai, spokesman for the governor of Nengarhar province of which Jalalabad is the capital.

The UN reported that a total of 2,959 civilians were killed in the war and 5,656 were wounded last year.

By comparison, there were 2,768 civilian deaths and 4,821 civilians wounded in 2012, and 3,133 deaths and 4,706 wounded in 2011.

The report blamed insurgents for 74 per cent of the civilian casualties. Afghan police and army were responsible for 8 per cent of the casualties and international coalition forces for 3 per cent, the report said, while 10 per cent could not be blamed solely on either side and the responsibility for the remaining 5 per cent was unknown.

The Taliban condemned the UN report, which a spokesman called American propaganda that was "completely upside down" in blaming the insurgency for most of the casualties.

"Very clearly there was an increase in our operations against the Afghan forces and foreign invaders, but also all our holy warriors were very careful to avoid civilian casualties," Taliban spokesman Zabiullah Mujahadid said in a statement. He added that "the majority of casualties among civilians are caused by foreign forces trying to get revenge."

The international military coalition, for its part, condemned the insurgents' "continuing disregard" for human life.

"The Taliban continue to attack mosques and health care facilities, they target schools by burning them down, emplacing IEDs (roadside bombs) near them and occupying them for insurgent activities," the coalition said in a statement

According to the report, roadside bombs laid by pro-Taliban forces again caused most civilian casualties, accounting for 34 per cent of deaths and injuries last year, while crossfire in battle accounted for 27 per cent. Suicide attacks accounted for 15 per cent of overall casualties, targeted attacks made up 14 per cent and pro-government air raids were responsible for 2 per cent. Unexploded ordnance detonations and "other" accounted for 4 per cent each.

Insurgent attacks against Islamic clerics and mosques tripled to 27 during 2013, causing the deaths of 18 people.

The sum total of 8,615 deaths and injuries in 2013 was the highest number of combined casualties since the UN began documenting them in 2009 after a sharp rise in violence.

But the deadliest year of the war was 2011, when 3,133 civilians died as the Taliban launched a fierce pushback with roadside bombs and other attacks against the increased number of international forces who wrested back much of the territory controlled by the insurgents.