NATO must investigate the killing of dozens of civilians during its air campaign in Libya last year and provide reparations to the people affected, Amnesty International said on Monday.

"Adequate investigations must be carried out and full reparation provided to victims and their families," said the rights group in a statement released one year after the first strike sorties were carried out by the alliance in Libya.

Amnesty's call drew a rebuttal from NATO, whose spokeswoman Oana Lungescu insisted in a statement that the coalition conducted a campaign in line with its UN mandate and international norms.

The watchdog said it has documented 55 cases of named civilians, including 16 children and 14 women, killed in air strikes in the capital Tripoli and the towns of Zliten, Majer, Sirte and Brega.

NATO attacks, which played a key role in helping rebels to bring down dictator Moamer Kadhafi, left a deep rift in the UN Security Council.

Russia, China, South Africa and India all say NATO's tactics breached UN resolutions. The United States, Britain, France and Germany insist their actions were legal and life-saving.

Amnesty International acknowledged that "significant efforts" were made by NATO to avoid civilian casualties, but faulted its failure to investigate strikes that killed innocent people.

"Victims and relatives of those killed by NATO air strikes remain in the dark about what happened and who was responsible," said Donatella Rovera, senior crisis response adviser at Amnesty.

The rights group urged NATO to carry out investigations to determine whether civilian casualties stemmed from a breach of international law, and if so to bring those responsible to justice.

"Many of the deaths occurred as a result of air strikes on private homes," where there was no evidence to indicate that the homes had been used for military purposes at the time of the attack, it said.

The NATO spokeswoman said the coalition responded to Amnesty earlier this month and insisted that the operation "was conducted in a manner fully consistent with the United Nations mandate and with international humanitarian law."

"We carried out our operations with utmost care and precision, as recognised by the International Commission of Inquiry on Libya," the spokeswoman said.

The commission concluded that NATO "'conducted a highly precise campaign with a demonstrable determination to avoid civilian casualties'," the spokeswoman said.

"The Commission found no violations of international law on the part of NATO," Lungescu added.

"NATO has looked into each credible allegation of harm to civilians which has been brought to our attention and will continue to do so," she said in a statement released in Brussels.

But concerning the specific Amnesty call for an investigation, Lungescu added that the coalition "did not have observers on the ground" in Libya during the conflict.

Furthermore she said Tripoli authorities should be the ones to address issues related to compensation.