The number of air strikes carried out by Afghan and US forces has surged since a new strategy was announced by US President Donald Trump in August last year.

But the UN has noted an increase in civilian casualties as more air strikes have been carried out.

In 2017, the UN recorded 631 civilian casualties from air strikes by pro-government forces, including international military forces, a 7% increase on 2016 even though total civilian casualties decreased by 9%. More than half of the casualties resulted from operations carried out by the Afghan army.

It was the highest number of civilian casualties from air strikes in a single year since the UN started systematic recording in 2009.