Prime Minister Stephen Harper confirmed Wednesday that two Canadian diplomats held hostage by African militants for four months have been freed.

Harper released few other details about the release of Robert Fowler, a United Nations special envoy to Niger who once served as Canada's ambassador to Italy, and his assistant, Louis Guay, at a news conference in Ottawa on Wednesday evening.

In the family's first public comments since the kidnapping, Fowler's wife, Mary, told CBC News from Ottawa on Wednesday night: "He called! I am beyond happy and cannot wait to see Bob!"

Canada received confirmation of the diplomats' release from the president of Mali, Harper said.

"Both are now in the hands of Malian authorities. They are being transferred to our care as quickly as possible."

Harper said he had spoken to the spouses of both men to convey his "sincere relief" at their release.

"I cannot imagine the ordeal they have suffered in recent weeks."

Liberal MP Dominic LeBlanc said he has been in contact with Fowler's family and they believe he is on his way to the Malian capital, Bamako.

"The family is certainly very enthusiastic about the news that they've been given and I know that they're looking forward to hopefully reuniting with Bob in the coming days," said LeBlanc, whose father, former Governor General Romeo Leblanc, is married to Diana Fowler, Robert Fowler's sister.

The Agence France-Presse news agency quoted an unnamed security source as saying that two women, one German and the other Swiss, were also released.

Fowler and Guay were travelling with their UN driver, Soumana Moukaila, in Niger on Dec. 14 when they were abducted. Their vehicle was found the same day, abandoned in good working condition about 40 kilometres northeast of Niger's capital, Niamey.

Moukaila was freed last month.

Both diplomats were dispatched to Niger in an attempt to broker a peace deal in the northern part of the country, where the Tuaregs, a minority of ethnic nomads, are fighting with the government.

Harper said he personally conveyed Canada's appreciation to the governments of Mali and Burkina Faso for their efforts in getting the men released.

Al-Qaeda's North African branch had claimed responsibility for the kidnappings of the two Canadians. The group, known by the French acronym AQMI, also said it was holding four European tourists taken in January.

A security source told AFP that the two women released in Mali on Wednesday were from that group, which included another Swiss man and a British man.

AQMI has not made any demands, but it has sought and received ransoms for past kidnappings of Western tourists.

While Canada does not condone such negotiation tactics, Harper told reporters Wednesday he can't speak for Mali or Burkina Faso.

"A negotiated release of the hostages was preferable to just about every other conceivable option in this case," he said.

However, "the Canadian government does not pay ransoms and it does not release prisoners…. But the decisions made by other governments are their decisions as sovereign countries and those questions must be put to those governments."

Despite AQMI's claims of responsibility, Niger's president, Mamadou Tandja, has blamed the Canadian diplomats' abduction on a rebel group of Tuareg nomads.

Tuareg rebels from the Front for Forces of Redress — who say uranium mining companies from Canada and other countries are pillaging their land without proper compensation for residents — retracted an initial statement claiming responsibility for the kidnapping.

But some Western intelligence officials believe the Tuaregs may have traded the hostages to al-Qaeda.

"It's all pretty murky in terms of who was responsible for the disappearance of these two Canadian diplomats," said Osler Hampson.

Fen Osler Hampson, a friend of Fowler, told CBC News that the diplomat had travelled extensively in Africa. Fowler would have handled the ordeal relatively well, said Osler Hampson, who is director of international affairs at Carleton University.

"He's someone who I think under these very trying circumstances would handle himself with the extraordinary professionalism for which he is known, and I suspect that he's also someone who would get to know his captors," he said.

"And I daresay they probably grew to like him, which is a good thing in these kinds of hostage situations, particularly when individuals' lives are at risk and they're in a very dangerous situation."