Hundreds of insurgents have been trained in Iran to kill NATO forces in Afghanistan; two Taliban commanders told a British Sunday newspaper.

The unnamed commanders told The Sunday Times that Iranian officials paid them to attend three-month courses in desert training camps in southeast Iran.

They were taught how to carry out complex ambushes and lay improvised explosive devices (IEDs), the roadside bombs which have been responsible for many of the deaths of British troops in Afghanistan.

One of the commanders told the newspaper that the military's crackdown in Pakistan was forcing Taliban leaders to turn to Iran for assistance and training.

"The military is pressuring the Taliban in Pakistan. It is certainly harder to reach places that were once easy to get into. I think more of my fighters will travel to Iran for training this year," he said.

A commander from Wardak in central Afghanistan said: "I found some elements of the training in Iran very useful, especially the escape and evasion techniques I was taught."

Both men said Iran also supplied them with weapons, often paying nomads to smuggle ammunition, mines and guns across the desert and mountain passes between Iran and western Afghanistan.

Iranian President Mahmoud Ahmadinejad has publicly backed his Afghan counterpart Hamid Karzai and the pair held talks in Kabul this month.

Before the U.S.-led invasion of Afghanistan in 2001, Taliban-Iran relations were very strained and deteriorated to a lowest level when members of the Taliban murdered 10 representatives of the Iranian consulate in the Afghan city of Mazar-e-Sharif.

After having repeatedly denied any knowledge of Iranian diplomats’ whereabouts, the Taliban admitted on Sept. 10, 1998 that its military forces had killed them.