London ? Prime Minister Tony Blair warned Iran on Thursday not to meddle in Iraq after declaring that explosive devices that have killed U.S.-led troops were similar to those used by the Iranian-linked militant group Hezbollah.

“There is no justification for Iran or any other country interfering in Iraq,” Blair said, vowing that Britain would not be intimidated into dropping demands that Tehran cooperate with the U.N. nuclear agency.

Speaking at a news conference with Iraqi President Jalal Talabani, Blair said new explosive devices used “not just against British troops but elsewhere in Iraq … lead us either to Iranian elements or to Hezbollah,” the Lebanese group backed by Syria and Iran.

Foreign Secretary Jack Straw said later that the same devices had been used against U.S. forces.

In Beirut, Hezbollah accused Blair of “lies.” Iran’s ambassador in London, Seyed Mohammad Hossein Adeli, said the charges “cannot be supported by either any political analyst or any concrete evidence.”

“We are against any kind of action which might jeopardize or destroy the stabilization process of Iraq,” the ambassador said.

U.S. officials have said in the past that they suspect Iran is the source for armor-piercing mine technology used by Hezbollah. But analysts say munitions used in Iraq are difficult to trace and that charges they are supplied by Iran could be politically motivated.