Nearly 2,400 Afghan civilians were killed or injured in May and June as fighting between Taliban insurgents and Afghan security forces escalated, the highest number for those two months since records started in 2009, the United Nationsinfo-icon said on Monday.

The UN's Assistance Mission to Afghanistaninfo-icon (UNAMA) said in a report it had documented 5,183 civilian casualties between January and June, of which 1,659 were deaths. The number was up 47 per cent from the same period last year.

The figures underscored the dire situation for Afghan civilians as intense fighting picked up in May and June after USinfo-icon President Joe Biden announced American troops would withdraw by September, bringing an end to 20 years of foreign military presence in the country.

"Of serious concern is the acute rise in the number of civilians killed and injured in the period from 1 May, with almost as many civilian casualties in the May-June period as recorded in the entire preceding four months," UNAMA said in a statement.

Heavy clashes around the country have taken place in the past two months as the Taliban launches major offensives, taking rural districts, border crossings and surrounding provincial capitals, prompting Afghan and US forces to carry out air strikes to try and push back the insurgents.

Negotiators have been meeting in Qatarinfo-icon's capital of Dohainfo-icon in recent weeks but diplomats have cautioned there has been little substantive progress since peace talks began in September.

"I implore the Taliban and Afghan leaders to take heed of the conflictinfo-icon's grim and chilling trajectory and its devastating impact on civilians," said Deborah Lyons, the UN Secretary-General's Special Representative for Afghanistan. "Unprecedented numbers of Afghan civilians will perish and be maimed this year if the increasing violence is not stemmed."