More Afghan civilians were killed by Afghan and North Atlantic Treaty Organisation (Nato) forces than by the Taliban and other militants in the first half of 2019, the UN mission said in a report released on Tuesday.

Most of the civilian casualties were apparently inflicted during Afghan and Nato operations against insurgents, such as airstrikes and night raids on militant hideouts. Insurgents often hide among civilians.

The report by the UN mission in Afghanistan said 403 civilians were killed by Afghan forces in the first six months of the year and another 314 by international forces, a total of 717. That is compared to 531 killed by the Taliban, an Islamic State affiliate and other militants during the same period.

It said 300 of those killed by militants were directly targeted. The Taliban have been carrying out near-daily attacks, mainly targeting security forces.

The Taliban have rejected calls for a ceasefire as they hold talks with the United States aimed at ending the 18-year war. An Islamic State affiliate has meanwhile launched attacks targeting security forces as well as minority Shias.

There was no immediate comment from the Kabul government, the Afghan military of the international coalition forces on the UN report.

The US formally ended its combat mission in Afghanistan in 2014 but still provides extensive air and other support to local forces battling both groups.

"Parties to the conflict may give differing explanations for recent trends, each designed to justify their own military tactics," said Richard Bennett, the human rights chief of the UN Assistance Mission in Afghanistan, which released the report.

He said the situation for ordinary Afghans would be improved "not just by abiding by international humanitarian law but also by reducing the intensity of the fighting".

The report said civilian deaths and injuries were down by a quarter from January to June 2019 compared with the same time last year, when casualties were at an all-time high. Civilian casualties attributed to insurgents dropped by 43 per cent.

The report said one in three casualties was caused by ground combat and a fifth were caused by roadside bombs. Aerial operations accounted for around 14 per cent of the casualties.

Meanwhile, there has been no claim of responsibility for an attack on Sunday night that apparently targeted the office of the Afghan president's running mate and former chief of the intelligence service.

The VP candidate, Amrullah Saleh, was safely evacuated from the scene of the attack, which left at least 20 people dead and about 50 wounded. Saleh is known for his fierce anti-Taliban stance.