WASHINGTON (AP) -- The Obama administration is pledging to
conduct a full investigation into a NATO attack that allegedly
killed 24 Pakistani troops.

Secretary of State Hillary Rodham Clinton and Defense Secretary
Leon Panetta in a joint statement on Saturday said they had each
spoken to their Pakistani counterparts to express their condolences
for the loss of life.

The incident was a major blow to American efforts to rebuild an
already tattered alliance vital to winding down the 10-year-old
Afghan war.

Islamabad called the bloodshed in one of its tribal areas a "grave infringement" of the country's sovereignty.

A NATO spokesman said it was likely that coalition airstrikes
caused Pakistani casualties, but an investigation was being
conducted to determine the details.