KABUL - Fighting in Afghanistan is spreading into populated areas, exacting a record toll on civilians, the UN warned Wednesday, as presidential candidates called on supporters not to escalate tensions after the disputed election result.
The country's political crisis and soaring civilian casualties have caused deep disquiet among Afghanistan's international backers who sent soldiers and billions of dollars of aid to the country since 2001.
Claims that a functioning state has been established to replace the harsh Taliban regime look at risk after presidential candidate Abdullah Abdullah rejected the June 14 election result alleging he was the victim of mass fraud.
Security gains also appear fragile as the final 50,000 NATO troops end their combat mission by December after 13 years of fighting that has failed to defeat the Taliban insurgents.
Underlining the extent of the violence plaguing Afghanistan, the UN report revealed that civilian casualties soared by 24 per cent in the first half of 2014.
Ground combat is now causing more deaths and injuries than improvised explosive devices (IEDs) in a worrying sign of spreading conflict, with women and children increasingly caught in the crossfire.
"The nature of the conflict in Afghanistan is changing in 2014 with an escalation of ground engagements in civilian-populated areas," warned Jan Kubis, the UN mission chief in Afghanistan.
"The impact on civilians, including the most vulnerable Afghans, is proving to be devastating."
In the first six months of this year, UNAMA documented 4,853 civilian casualties -- up 24 per cent over the same period in 2013.
The toll included 1,564 deaths and 3,289 injuries, with ground engagements causing two out of every five civilian casualties in 2014.
Fears that Afghanistan could see a return to the ethnic bloodshed of the 1992 -1996 civil war have grown during the deepening election crisis.
Abdullah Abdullah, a former anti-Taliban resistance fighter, came second in preliminary results to Ashraf Ghani, but Abdullah said the election was fraudulent and that he expected to become the next president.
Ghani attracts much of his support from the Pashtun tribes of the south and east, while Abdullah's vote base is among the Tajiks and other northern Afghan groups -- echoing the ethnic divisions of the civil war.
As NATO troops pull out, the coming months are expected to be a test of the fledgling Afghan government forces, who have been trained by the US-led military coalition since the Taliban were ousted in 2001.
Recent weeks have seen fierce fighting in the southern province of Helmand, as the Afghan army and police counter-attack after an offensive by 800 Taliban fighters in an area from which US troops withdrew only back in May.
"The fight is increasingly taking place in communities, public places and near the homes of ordinary Afghans, with death and injury to women and children in a continued disturbing upward spiral," said Georgette Gagnon, director of human rights for UNAMA.
As anger among his supporters has increased over alleged fraud, Abdullah's campaign team on Wednesday appealed for calm and said no street protests would be held.
"We are calling for people not to protest and to wait for a few days to see what decisions are made," a press official from Abdullah's team told AFP.
Abdullah's poll rival Ashrah Ghani, who says he won the election fairly, also called for the election timetable to be respected.
The final result is due out on about July 24 after adjudication of complaints and an anti-fraud audit.
Abdullah's supporters took the street 10 days ago when reports emerged that Ghani was well ahead in the vote count, though protests have so far been peaceful.
President Hamid Karzai, who is constitutionally barred from a third term in office, has stayed publicly neutral in the lengthy election, but Abdullah supporters accuse him of fixing the run-off vote in Ghani's favour.
US President Barack Obama warned the two rivals that violence or taking "extra-constitutional means" would result in him stopping US assistance to the war-torn country.
In phone calls to Ghani and Abdullah, Obama "stressed that the United States expects a thorough review of all reasonable allegations of fraud to ensure a credible electoral process", the White House said in a statement.