Human Rights Watch on Thursday called for a probe into alleged abuses including summary executions after reports of reprisal killings by French-backed Malian forces.

"All sides have committed very serious violations, and we believe that they should be investigated," Tiseke Kasambala, the group's director for Africa, said in Johannesburg.

Rights researchers have also documented cases of recruitment of child soldiers and rape, she said.

She also called on the French intervention forces "to ensure that they minimize civilian atrocities and deaths in their intervention in the last Islamist bastion in Mali's north".

Meantime the US-based group's executive director Kenneth Roth expressed fears that reprisals would continue as the Islamist rebels are pushed out.

Islamist groups allied to Tuareg rebels last year inflicted a string of defeats on the Malian army on their way to taking control of the north of the country and there are fears of reprisals for that humiliation.

Researchers on the ground, say that Malian troops "have been involved in a series of reprisal killings and reprisal disappearances. We are fearful there will be more of that", he told journalists in London.

Islamists have also been accused of violations.

"We've been deeply concerned about the extreme form of Sharia implemented by the jihadists," Roth said. "We've seen executions, amputations, the destruction of cultural property."

Roth spoke at a press conference to unveil his group's annual report on human rights practices across the world.

As France prepares to pass military duties in Mali to a multinational African force, Roth called on international bodies such as the African Union to put "serious pressure" on Malian forces to respect basic rights.

"We've been actively pushing, as international troops go in, for international human rights monitors to join them," he said.

The group warned that the country stands on the tipping point of a human rights crisis.

The United States has called for Malians to refrain from revenge attacks on Tuaregs or other ethnic minorities.

France said this week that it supports the swift deployment of an international observation mission to monitor human rights abuses as its troops prepare to hand over to the African-led force for Mali (AFISMA).