Washington did not know about advanced negotiations to release South African teacher Pierre Korkie before he was killed in a failed U.S.-led mission to rescue hostages held by al-Qaeda in Yemen, the U.S. ambassador to South Africa said on Monday.

Pierre Korkie, 56, and American journalist Luke Somers, 33, died of wounds after being shot during a special forces raid intended to free Somers shortly after midnight on Saturday. Washington says they were killed by their captors, members of al-Qaeda in the Arabian Peninsula (AQAP).

Another 11 people, including a woman, a 10-year-old boy and a local al-Qaeda leader, were also killed during the raid in the village of Dafaar in Shabwa province, a militant stronghold in southern Yemen.

American journalist Luke Somers, 33, (above) and South African teacher Pierre Korkie, 56, were shot and killed by their captors during the raid intended to secure their freedom, U.S. officials said. (Jaber Ahmad Ghrab/Associated Press) Gift of the Givers, a relief group negotiating Korkie's release on behalf of his family, said the teacher had been due to be handed over on Sunday, hours after the raid.

U.S. Ambassador to South Africa Patrick Gaspard said Washington acted swiftly to free Somers because it had information that he was going to be killed by his captors.

"We were unaware of negotiations for the release of Pierre Korkie and we were also not aware that Pierre Korkie was being held in the same space as Luke Somers," Gaspard told 702 talk radio.

U.S. officials have said they were aware a second hostage was at the location but did not know that it was Korkie.

Korkie's wife does not blame U.S.

Gift of the Givers and Korkie's wife, Yolande, who was released in January after being held with her husband, said they didn't hold the U.S. responsible.

South African Pierre Korkie was also killed in the hostage rescue attempt. (Korkie family/Associated Press) "There is no accusation towards anybody. Mrs. Korkie is not in a position to say they (U.S.) were wrong," Korkie family spokesman Daan Nortier told Reuters.

"Mrs Korkie, as a Christian, applies the biblical principle of forgiving ... even for his captors."

Korkie's body was due to be repatriated to South Africa by U.S. authorities later on Monday, Nortier said.

Gift of the Givers spokesman Imtiaz Sooliman confirmed that Washington had not been informed about the negotiations.

"I don't judge them for making the raid or have any anger towards them. They were working in the best interests of their citizen," Sooliman told Reuters. "Any other government would do something similar."

AQAP, formed in 2006 by the merger of the Yemeni and Saudi wings of al-Qaeda, has for years been seen by Washington as one of the militant movement's most dangerous branches.

Western governments fear advances in Yemen by Shia Muslim Houthi fighters with links to Iran have bolstered support among Yemeni Sunnis for AQAP, which has established itself in parts of Yemen, including Shabwa where the raid took place.

At least two more hostages are being held by the group.