Empty graves found at Pak airstrike site

But there was no information about the identities of the insurgents who died in the raid on a remote tribal village, despite initial US intelligence reports that Al-Qaeda's Egyptian number two Ayman al-Zawahiri may be among them.

Officials said local militants may have shifted the bodies before burial to stop Pakistani or US authorities DNA testing the remains and finding out who was killed in Friday's missile attack.

Residents of Damadola village in Bajur tribal agency, however, have reported that 18 civilians died in the attack, for whom as many graves were dug, and that no militants were in the area.

"The residents dug 18 graves but buried 16 people and two graves were left vacant before they covered them over," a senior security official told AFP, citing a report by intelligence officials in the region.

On Tuesday the regional administration chief of Bajur said the missile strike was aimed at foreign militants invited to a dinner and that four or five were killed -- the first such public confirmation by Pakistan.