The Taliban dismissed on Sunday a UN report that roadside bombs are causing most civilian casualties in Afghanistan as "Western propaganda."

Taliban spokesman Zabiullah Mujahid claimed that the insurgents only use the weapons to target foreign troops and the Afghan security forces.

"By spreading such propaganda they are trying to prevent us from planting bombs which cause the deaths of invaders in our country," he said in an emailed statement.

On Saturday, the UN mission in Afghanistan urged the insurgents to end the use of roadside bombs, also known as improvised explosive devices or IEDs, saying they were by far the biggest killer of civilians in the conflict. The organization used the term in reference both to bombs detonated by remote control and landmines that go off when a vehicle goes over them.

The call came a day after 19 civilians died and 15 were injured when their bus struck a mine in northern Balkh province on Friday. The UN said that blast was caused by an IED planted on a busy public road and set off by a pressure plate. It said the bomb was "consistent with documented patterns and tactics of choice by the Taliban."

Insurgent-placed homemade bombs continue to be the deadliest weapon for civilians, according to the world body. IEDs killed 340 civilians and injured a further 599 over the past nine months, an increase of almost 30 per cent compared to the same period last year, the UN said.

But the Taliban spokesman denied that any insurgents were operating in the area of Balkh province where Friday's blast occurred.

He also said the Taliban use only remote-controlled roadside bombs which -- unlike the devices automatically activated by pressure-plates -- allow a bomber to choose the time of the blast and specifically target coalition troops and their Afghan allies.

About half of the casualties suffered by coalition forces in recent years have been caused by roadside bombs and mines.