French Foreign Minister Laurent Fabius condemned "the cowardly attack," which came just before Sunday's second round of legislative elections, meant to restore constitutional order in Mali.
The U.N. Security Council and Secretary-General Ban Ki-moon also condemned the bombing "in the strongest terms," according to two separate statements.
"All those responsible for this criminal act must be brought to justice," Ban's office said. The statement said two peacekeepers were killed and at least 11 others were wounded, including seven peacekeepers and four members of the Malian national guard.
The 15-member Security Council called on Mali's government to "swiftly investigate the attack and bring the perpetrators to justice," according to a statement released by the 15-member body.
Separately, at least 80 Islamic radicals attacked a Tuareg camp in the town of Teringuite, also in northern Mali, killing two people, according to the intelligence official. He said that fighters from the Movement for Oneness and Jihad in West Africa attacked the camp on Saturday.
He said the group was led by Abou Dardar, a commander who was among those who invaded and held the famous city of Timbuktu in northern Mali in 2012. It wasn't immediately clear if there were casualties from the second attack.
The back-to-back assaults are the worst to have rocked northern Mali in recent weeks, and come as France rushes troop to the Central African Republic, its former colony, where at least 600 have died in a week of sectarian violence. The French military deployed in Mali, another ex-colony, in January.
The French military, assisted by African troops, succeeded in chasing the rebels from almost all the areas they controlled, except Kidal, which remains at the heart of the conflict.
Analysts had long predicted that the al-Qaida linked fighters who controlled northern Mali for 10 months last year had not been defeated, just dispersed by the French-led intervention, and are just waiting for the international community to look the other way before staging a comeback.
It's too early to tell if the attacks in Kidal and Teringuite were coordinated or if indeed they mark a new phase in the hostilities.