United Nations chief Ban Ki-moon is demanding an end to attacks on U.N. peacekeepers in northern Mali, after a bomb blast killed five peacekeepers on Thursday.
In a statement, the secretary-general said he is "outraged" by the roadside bomb attack near Aguelhok, in the Kidal region, that killed the five Chadian peacekeepers and injured three other soldiers.
A similar attack in the same area killed four U.N. peacekeepers earlier this month.
Ban called Chadian President Idriss Deby on Friday and expressed his gratitude to Chadian forces that are operating in what he called "particularly difficult circumstances."
The secretary-general called on Malian rebel groups to help prevent terrorist attacks, in line with a commitment the groups made in a declaration signed Tuesday.
The rebels and Malian government are holding talks in Algiers aimed at clinching a lasting peace agreement.
The United States also strongly condemned Thursday's bomb attack. A State Department spokeswoman Friday called on all parties to cease hostilities and fully engage in the peace process.
Torn by ethnic rivalries, a Tuareg rebellion and an Islamist insurgency in its vast desert north, Mali has struggled for stability and peace since a military coup in 2012.
The U.N. says bomb attacks have killed 21 peacekeepers and wounded another 84 in Mali since the U.N. mission began there in July 2013.