Tuareg rebels, militias and Islamist groups are committing war crimes in Mali's lawless north, including summary executions and rapes, Human Rights Watch said on Monday.
Even government troops in the north, parts of which are controlled by Tuareg separatists, Arab militias and armed Islamists are also flouting rights, the New York-based organisation said.
"Armed groups in northern Mali in recent weeks have terrorized civilians by committing abductions and looting hospitals," said Corinne Dufka, senior Africa researcher at Human Rights Watch.
"The commanders of these groups need to stop the abuses, ensure discipline over their fighters, and appropriately punish those in their ranks responsible for these crimes."
A statement said the forces who overran the north after a March 22 putsch in Bamako, the capital in Mali's south, "have committed numerous war crimes, including rape, use of child soldiers, and pillaging of hospitals, schools, aid agencies, and government buildings."
It said HRW had got "credible information that Malian army soldiers have arbitrarily detained and, in some instances, summarily executed ethnic Tuareg members of the security services and civilians.
Much of the north remains in the hands of two armed groups -- Islamists Ansar Dine and the National Movement for the Liberation of Azawad (MNLA), Mali's main Tuareg rebel group.
The MNLA earlier declared independence in the north, a vast swathe of desert it calls Azawad, which it captured along with Ansar Dine, a much smaller group.
Ansar Dine, an Islamist group, subsequently took control of Timbuktu. It says it rejects independence for the north and says it is fighting for Islam and to impose sharia law.
The statement quoted witnesses as saying that the MNLA was responsible for much of the killings and looting and had children aged as young as 13 among its fighters.
"Ansar Dine fighters took several measures to protect civilians from the widespread looting, sexual violence, and other abuses by the MNLA, Arab militias, and common criminals," it said.
But witnesses said that Ansar Dine members also "executed two men in (the northern town of) Gao and amputated the hands of an MNLA rebel in Kidal as part of its crackdown.
"Gao residents said that in early April, Ansar Dine had cut the ear of a woman for wearing a short skirt and flogged men who had consumed alcohol and engaged in petty theft."