In previous statements, NATO said it watched the homes carefully before attacking and saw “military staging areas.” It also said that it reviewed the strikes and that claims of civilian casualties were not corroborated by “available factual information.” When asked what this information was, the alliance did not provide it.

Mr. Gafez issued a challenge. An independent review of all prestrike surveillance video, he said, would prove NATO wrong. Only civilians were there, he said, and he demanded that the alliance release the video.

Ms. Younes said the dispute missed an essential point. Under NATO’s targeting guidelines and in keeping with practices the alliance has repeatedly insisted that it followed, she said, if civilians were present, aircraft should not have attacked.

The initial findings on the Majer strikes, part of the United Nations’ investigation into actions by all sides in Libya that harmed civilians, have raised questions about the legality of the attack under international humanitarian law, according to an official familiar with the investigation.

Homes as Targets

NATO’s strikes in Majer, one of five known attacks on apparently occupied residences, suggested a pattern. When residential targets were presumed to be used by loyalist forces, civilians were sometimes present — suggesting holes in NATO’s “pattern of life” reviews and other forms of vetting.

Airstrikes on June 20 in Surman leveled homes owned by Maj. Gen. El-Khweldi el-Hamedi, a longtime confidant of Colonel Qaddafi and a member of his Revolutionary Council. NATO has said the family compound was used as command center.

The family’s account, partly confirmed by rebels, claimed that the strikes killed 13 civilians and wounded six more. Local anti-Qaddafi fighters corroborated the deaths of four of those killed — one of the general’s daughters-in-law and three of her children.