The number of civilians killed and injured in Afghanistan rose by a quarter in the first six months of this year, according to the United Nations.

Homemade Taliban landmines are still the deadliest threat to ordinary Afghans, and the insurgents caused around three-quarters of all recorded civilian losses and injuries, said the UN in a report that charts rising violence in the wake of Nato troops’ accelerating departure from the country.

But there was a sharp increase in civilians harmed in ground battles between Afghan government troops and insurgents, the second leading cause of casualties and a worrying new trend as fighting intensifies and insecurity spreads.

“Civilians again increasingly bore the brunt of the armed conflict in Afghanistan in early 2013,” the report warned. “[They] experienced the grim reality of rising civilian deaths and injuries coupled with pervasive violence which threatened the lives, livelihood and wellbeing of thousands of Afghans.

“More armed groups, roads blocked by checkpoints or lined with IEDs [improvised explosive devices], increased harassment and intimidation and not enough protection from Afghan National Security Forces in some areas led to increasing harm to civilians. Anti-government elements [insurgents] continued to deliberately kill, injure, threaten and intimidate civilians with impunity.”

Overall 1,319 civilians were killed and a further 2,533 injured between January and June - numbers close to a record casualties in the same period in 2011, and reversing a decline last year. Women and children suffered particularly, with deaths and injuries rising much faster than the overall casualty totals.

Targeted killings by insurgents increased by around a third, with more than 400 people killed and injured, and assaults on government workers and buildings also rose fast.

“Deliberate attacks on civilians including civilian government officials are prohibited at all times and may amount to war crimes,” the UN report said, highlighting assaults on courtrooms and mullahs carrying out funeral services for members of the security forces killed in action among several potential violations.

The departure of Nato combat troops, who are all due home by the end of 2014, appears to have prompted heavy fighting in some of the areas they have left as insurgents and government forces push “to secure or regain territory” for the long term, the UN said.

“The increase in civilian casualties from ground engagements may also be linked to the escalated pace of transition or closure of military bases in 2013, combined with the scaling back of international military operations,” the report said.

The subsequent fighting, often after Taliban attacks on government forces or outposts, was responsible for a quarter of all recorded deaths and injuries.

Civilian deaths directly at the hands of government forces and their foreign backers fell slightly. But a big increase in injuries meant that overall civilian casualties by pro-government troops also rose in the first half of the year, the UN said.

One concern is an increase in deaths and injuries of Afghans from unexploded weapons at former Nato bases and firing ranges that have been closed but not fully cleared, or sites where there have been ground fighting in the past. More than 40 people have been killed and the UN warned it may be under-reporting these casualties.

“The need to clear ERW [explosive remains of war] from firing ranges prior to base closure is of particular urgency,” the report said. “Considering that Afghan children tend to collect scrap metal for money, any scrap metal remaining in these areas poses a high risk.”

Deaths and injuries caused by Afghan local police, and foreign-funded militia groups—formed to protect their home areas against the Taliban—also rose by nearly two-thirds from 2012 levels.

Human rights activists have long called for greater government controls on the semi-informal but locally powerful groups, and the UN report documented crimes including “murder, torture, rape, threats, intimidation, harassment, forced labour, extortion and illegal taxation”.

The bleak outlook for Afghan civilians is made worse by the lack of an official body to investigate allegations of casualties, said the report.

“Despite Afghan forces leading almost all military operations countrywide, a permanent structure does not exist in relevant ANSF [Afghan National Security Forces] bodies to systematically investigate allegations of civilian casualties, initiate remedial measures and take follow-up action.”

The report called on the Kabul government to set one up immediately, and also warned that Nato needs to keep a mechanism for investigating civilian casualties after 2014.

Foreign forces are expected to stay on under a Nato mission to train and advise Afghan forces, and the UN also called on them to boost Afghan abilities to detect and destroy the Taliban's deadly landmines.

By arrangement with the Guardian