Kabul: Afghanistan's spy agency on Monday said a senior foreign ministry diplomat and three other government officials have been arrested over charges of spying for neighbouring Iran and Pakistan.

The men were detained "on charges of spying for neighbouring regions" and "the arrests were made with concrete evidence", the agency's spokesman, Lutfullah Mashal said, speaking in English.

The spokesman refused to provide details but a senior intelligence official speaking to an agency under condition of anonymity said the men worked for Iran and Pakistan – both accused of interference in the troubled nation.

"One of them is a senior diplomat at the foreign ministry, he's the deputy head of the Asia desk. The others are government employees in the provinces of Nangarhar (in the east) and Herat (in the west)," the official said.

The arrests were made a month ago, he said.

The official said the senior diplomat and two of the three other men were providing intelligence for Pakistan's ISI military intelligence agency, which Afghans accuse of secretly helping Taliban insurgents in Afghanistan.

The foreign ministry was not immediately reachable for comment.

The Taliban, who were in power from 1996 until 2001 when they were ousted in a US-led invasion, are waging an insurgency to topple President Hamid Karzai's Western-backed government.

The fourth person was arrested in Herat, Afghanistan's western trading hub on the border with Iran and Turkmenistan.