Iran is supplying Iraqi insurgents with weapons technology used to kill US troops, a senior American diplomat said today as he warned Iran against interfering in Iraq.
"We have picked up individuals who we believe are giving very sophisticated explosive technology to Shia insurgent groups who then use that technology to target and kill American soldiers," said Undersecretary of State Nicholas Burns.
"It's a very serious situation. And the message from the United States is, Iran should cease and desist."
The United States has been tracking Iranian involvement in in Iraqi insurgent attacks for about two years and has found increasing evidence that Iran has given assistance to Shias in Southern Iraq, Mr Burns said in an interview.
"They have attacked British soldiers near Basra, and they've now begun to mount those operations throughout the country - at least in the Baghdad region as well," Mr Burns said.
Washington officials have claimed that Iran is providing Shias with high-grade explosives capable of penetrating the armour on military vehicles.
The Bush administration has repeatedly warned Iran against fuelling violence in Iraq, and US forces have detained a number of Iranian officials in raids over the past month.
"We warned Iran privately on a number of occasions over the last year and a half, and the Iranians, of course, did not appear to listen to that, so now we've begun to detain those Iranian officials," Mr Burns said in the interview.
"We think it's absolutely within our rights to do so under Article 51 of the UN charter, which is self-defence."
Washington accuses Tehran of undermining efforts to stabilise Iraq and of pursuing nuclear weapons. Iran says its nuclear ambitions are for generating electricity.
President Bush has said that the conflict over Iran's nuclear ambitions can be resolved peacefully, but he repeated a vow the the United States would respond firmly if Iran stirs up violence in Iraq.