On Monday, Amnesty International called on all sides in the conflict to protect civilians. The rights groups also urged the international community to support the deployment of human rights monitors.
"There are real concerns that the fighting might lead to indiscriminate or other unlawful attacks in areas where members of armed Islamist groups and civilians are intermingled," Paule Rigaud, Amnesty International's deputy director for Africa, said in a statement.
"The international community has a responsibility to prevent a fresh surge in abuses during this new phase of the conflict. Forces involved in armed attacks should avoid indiscriminate shelling at all costs, and do their utmost to prevent civilian casualties," he added.
A French colony until 1960, Mali had military rulers for decades until its first democratic elections in 1992. It remained stable politically until March, when a group of soldiers toppled the government, saying it had not provided adequate support for them to fight ethnic Tuareg rebels in the country's largely desert north.
Tuareg rebels, who'd sought independence for decades, took advantage of the power vacuum and seized swaths of land. A power struggle then erupted in the north between the Tuaregs and local al Qaeda-linked radicals, who wound up in control of a large area as the Tuaregs retreated.
The United Nations says amputations, floggings and public executions -- like the July stoning of a couple who had reportedly had an affair -- became common in areas controlled by radical Islamists. They applied a strict interpretation of Sharia law in banning music, smoking, drinking and watching sports on television, and damaged Timbuktu's historic tombs and shrines.
A recent video posted online purports to show Islamic extremists from the Movement for Unity and Jihad in West Africa cutting off the hand of a thief and flogging another man, accused of having sexual relations with a girl with "mental deficiencies."
In the video, the supposed crimes of the men are read aloud before the punishments are carried out. A small crowd, including children, cheer.
Already, the armed groups' activity and a pervasive drought have displaced hundreds of thousands of Malians.
And the Islamists' movement southward has raised concerns among leaders in West Africa and elsewhere, some of them calling for swift and decisive military intervention in support of Mali's government, based in Bamako.
The U.N. Security Council last month authorized a one-year military peacekeeping mission in the country. Members of ECOWAS, the Economic Community of West African States, pledged thousands of troops, and the Security Council has urged other nations to contribute forces as well.
The Security Council met Monday to receive an update on Mali. Following that meeting, the U.S. ambassador to the United Nations, Susan Rice, said there may be a need for a new Security Council resolution.
The United Nations said preparations are under way for a U.N. multidisciplinary team to go to Bamako soon.
Nigeria, Niger, Burkina Faso, Togo, Senegal and Benin are among the countries that have pledged to send troops, French Foreign Minister Laurent Fabius told reporters Monday.
Mali's northern neighbor, Algeria, will close its border with Mali, Algeria's state news agency, Algeria Press Service reported.
A spokesman for Germany's Foreign Ministry said the country's leaders were considering offering medical, logistical and humanitarian aid to Mali.
Two British military transport aircraft have been assigned to help with the French troop deployment, but no British forces will be in a combat role, said Mark Simmonds, minister for Africa for the British Foreign & Commonwealth Office.
"The ferocity and fanaticism of the extremists in northern Mali must be not be allowed to sweep unchecked into the country's capital," Simmonds told British lawmakers Monday. "France, which has an historic relationship with Mali, is quite rightly in the lead. In the coming days, we will be focused on the regional and international diplomacy we must achieve to check this emerging threat."