Record numbers of civilians have been killed and injured in Afghanistan in intense fighting since 1 May, when international forces began their final drawdown and the Taliban launched a major offensive.

The heavy toll so far comes largely from battles in rural areas, according to the UN. If the conflict were to spill into more densely populated towns and cities, the consequences could be catastrophic, it says in its report, The Protection of Civilians in Armed Conflict.

Swathes of the country have fallen to the insurgents since they launched their offensive two months ago to coincide with the original deadline authorities set for US and other forces to leave the country. The UN report is the first nationwide account of the impact of the fighting on civilians.

It notes near-record levels of casualties in the first six months of the year, with insurgent groups responsible for well over half of the deaths and injuries. It also says the “acute rise” in the two months since 1 May is of particular concern.