Reports Iranian arms reaching Taliban worry U.S.

KABUL (Reuters) - The United States is concerned over reports that Iranian-made weapons are crossing the Afghan border and reaching Islamist Taliban insurgents, a top U.S. diplomat said on Tuesday.

Iran supported Afghan groups fighting the Taliban in the 1990s and played a crucial role in helping to topple the Taliban's Sunni government, ousted by the 2001 U.S.-led invasion, by supporting their Mujahideen foes.

The Shiite Islamic Republic has repeatedly in the past denied accusations by U.S. officials that it is arming the resurgent Taliban, who are largely active in southern and eastern areas close to the border with Pakistan.

"We are concerned by reports, which we consider to be reliable, of Iranian explosively formed projectiles and other kinds of military equipment coming from Iran across the border and coming into the hands of the Taliban," U.S. Deputy Secretary of State John Negroponte told reporters on a visit to Kabul.

He did not elaborate.

The Taliban, like the Iranian government, have rejected U.S. reports that they are acquiring Iranian arms, and Afghan President Hamid Karzai has hailed relations with Iran as good.

Iran was among the Islamic countries and Western powers that provided arms and funds to some Afghan factions during the invasion of Afghanistan by the Soviet Union in the 1980s, and explosives experts are still clearing Iranian-made landmines laid during the 1990s.

Violence has surged in Afghanistan in the past 19 months, the bloodiest period since the Taliban's ouster.

Washington is leading international efforts to isolate Iran over its disputed nuclear program and accuses it of fomenting instability in Iraq.

The West says Iran is trying covertly to develop nuclear weapons, while Iran says its nuclear program is for electricity generation.