Afghanistan's Ambassador to Canada appears to be cautious about blaming Iran for improvised explosive devices (IEDs) being used in attacks against Afghan and NATO soldiers in his country.

On Tuesday, Defence Minister Peter MacKay alleged that many IEDs in Afghanistan have come from Iran.

"We're very concerned that weapons are coming in from Iran, we're very concerned these weapons are going to the insurgents and keeping this issue alive," he told reporters in Kandahar, where he was paying a Christmas visit to Canadian troops.

But Omar Samad, the top Afghan diplomat in Canada, told CTV Newsnet on Wednesday that there is no evidence about where the IEDs actually originated and who brought them to Afghanistan.

"Iran is a neighbor and we have good relations," he said. "The point is -- and the questions that have to be answered (and) are being looked at as far as who is involved in this. Is this a smuggling issue? Is this a policy issue by some government? Is this maybe an attempt by arms dealers to bring arms from a certain source?"

The Afghan government is working with its partners, including Canada, in attempting to find answers to those questions, he said.

Samad pointed out that Iran, which shares a 1,000-kilometre border with his country, hosts one million Afghan refugees. He said it must still be determined whether or not certain groups in other countries are involved in sending weapons to Afghanistan or if governments are involved.

U.S. Ambassador David Wilkins accompanied MacKay to Afghanistan -- at Canada's request -- for the Christmas Day visit with troops. In the past the U.S. has accused Iran of supplying weapons and materials for IEDs to insurgents in Afghanistan and Iraq.

U.S. officials have also accused Iran of having a nuclear weapons program, which was refuted by an intelligence assessment by 16 American spy agencies just a few weeks ago.

Canada had not linked Iran to weapons in Afghanistan before MacKay's and Wilkins' trip.

MacKay said in French that Canada has repeatedly demanded that Iran halt the flow of weapons to Afghanistan.

But Samad said more investigation is needed before assigning blame to a specific source.

"First, we have to establish the facts, and then we will look at the options that exist," he said.

Iran's Shiite government has historically had frosty relations with the Taliban, which is the main insurgent force fighting against NATO and Afghan national forces. The Taliban and al Qaeda insurgents are composed of Sunni Muslims, who have traditionally been antagonistic towards Iran's Shiite Muslims.

MacKay also warned Pakistan to stop supplying weapons to Afghanistan, which has a strained relationship with the government in Kabul in the past few years.

Diplomat explusions

Afghanistan ordered two European diplomats out of the country on Tuesday.

Samad said the two officials -- one with the United Nations and the other with the European Union -- were "involved in activities that they were not supposed to be involved in as employees belonging to those organizations."

The two diplomats visited Helmand province earlier this week, meeting with local leaders. The Taliban had controlled the region until recently when the government reasserted control.

Samad said he doesn't believe the expulsion of the diplomats will hurt his country's relationship with international organizations or other countries.

"I think that we all should realize that there's a very important mission, a very complex mission that we are all involved in, and that the Afghan people and the Afghan government are in the driver's seat," he said.

The Afghan government wants to make sure that international governments and diplomats coordinate their efforts with Kabul, he said.

The two diplomats will likely leave the country within the next two days.