KABUL (REUTERS) - Afghan forces backed by the United States killed two senior Taleban leaders and at least 38 fighters of the hardline insurgent group in joint air strikes conducted in the northern and western regions of Afghanistan, officials said on Sunday (Sept 15).

The operations, launched on Saturday night, were aimed at foiling attacks planned by the Taleban on Afghan forces, said a senior security official in the capital Kabul, adding that clashes have escalated following the collapse of diplomatic talks between the US and the Taleban.

The defence ministry in a statement said that the Taleban's designate governor for northern Samangan province, Mr Mawlavi Nooruddin, was killed along with four fighters in an air strike in Dara-e-Soof Payeen district.

But the Taleban denied the governor had been killed.

"He (Nooruddin) is alive," Mr Zabihullah Mujahid, a Taleban spokesman, said in a statement.

In a separate incident, Mr Mullah Sayed Azim, a Taleban designate governor for Anar Dara district in western Farah, was killed in a joint Afghan and foreign force raid.

"Sayed Azim was killed along with 34 other insurgents in Anar Dara," said Mr Mohibullah Mohib, a spokesman for the Farah provincial police.

Senior security officials in Kabul said several joint operations will be launched against Taleban and Islamic State in Iraq and Syria (ISIS) fighters to prevent attacks on Afghan forces and civilians ahead of the presidential polls on Sept 28.

Fighting picked up in several parts of Afghanistan last week after US President Donald Trump's abrupt cancellation of talks with the Taleban aimed at withdrawing US troops and opening the way to end to a 18-year war in Afghanistan.

Last week, the Taleban killed four Afghan special force members in a car bomb blast.