The number of Afghan civilians killed and wounded surpassed 11,000 in 2015 - the highest number recorded since the US-led invasion more than 14 years ago.

The United Nations said in its annual report released on Sunday there were 3,545 civilian fatalities and 7,457 people wounded with children paying a particularly heavy toll.

The total of 11,002 civilian casualties marked a four percent rise over 2014, the previous record high, the report said.

One-in-four casualties was a child, while one-in-10 was female, it said, with the UN's special representative for Afghanistan Nicholas Haysom calling the figures "unacceptable".

"We call on those inflicting this pain on the people of Afghanistan to take concrete action to protect civilians and put a stop to the killing and maiming of civilians in 2016," said Haysom.

"Unprecedented numbers of children were needlessly killed and injured last year," said Danielle Bell, the UN's director of human rights in Afghanistan. "Other children suffered the loss of parents ... one in 10 casualties was a women."

Violence has increased since the drawdown of US and NATO forces over the past few years, as the Afghan army and police struggle against a surge in attacks by anti-government fighters.

An estimated 59,000 civilian causalities have been recorded since the United Nations began tracking the total in 2009.

PHOTO CAPTION

Afghan children are reflected in flood water as they make their way to play on the outskirts of Kabul, Afghanistan, Sunday, Jan. 31, 2016. (AP Photo)

Al-Jazeera