Canada is launching a board of inquiry to find out how a training mission in Afghanistan turned into a tragedy that took the lives of four Canadian soldiers.

Defence Minister Art Eggleton says former chief of defence staff Maurice Baril will head the investigation into the tragedy near Kandahar. Four others will be named to the board soon.

Eggleton says the Department of National Defence has already launched its own parallel investigation.

An F-16 similar to the one involved in Thursday's incident
An F-16 similar to the one involved in Thursday's incident

The four soldiers died when a U.S. National Guard F-16 fighter jet dropped either one or two 250-kilogram laser-guided bombs during an overnight training exercise. Dead are Sgt. Marc Leger, Cpl. Ainsworth Dyer, Pte. Richard Green, and Pte. Nathan Smith.

Eight other soldiers were wounded. Six of them arrived for medical treatment at an American military hospital in Germany Thursday. Governor General Adrienne Clarkson was there to meet them. Two of the soldiers are in very serious condition. The other four could be on their way home by Saturday.

The wounds of the two others are minor and they've been treated in Afghanistan. The bodies of the four soldiers who were killed are expected to arrive in Germany Friday, before being flown back to Canada.

Canadian flag at half-mast in Kandahar
Canadian flag at half-mast in Kandahar

According to an American report, two U.S. fighters spotted the live fire and asked a command centre for permission to strafe the area. Permission was denied. But the report says the jets thought they were being attacked and one of them bombed the area.

The U.S. jet was reportedly not involved in the training exercise on the ground.

Marley Leger, the wife of Sgt. Leger, told CBC News that her husband was 29 and had been a soldier for eight or nine years. She said family members were on their way to her home in Edmonton.

Joyce Clooney, the grandmother of Pte. Richard Green, says she got a letter from him just last month, reassuring her that he was doing well.

"He just wanted to be somebody, just to do something important," she said.

The victims were all members of the Third Battalion of Princess Patricia's Canadian Light Infantry, based in Edmonton.

The Defence Department said the deaths were the first loss of Canadian lives in an offensive operation since the Korean War in the 1950s.

The injured are listed as: Sgt. Lorne Ford, Cpl. René Paquet, Master Cpl. Curtis Hollister, Cpl. Brett Perry, Pte. Norman Link, Cpl. Shane Brennan, Master Cpl. Stanley Clark, and Cpl. Brian Decaire.