The United Nations Security Council has condemned an attack that left two Malian citizens and one Togolese peacekeeper dead.

In a press statement issued on Monday, the council called on the government of Mali to swiftly investigate the attack and bring the perpetrators to justice. The statement says that attacks on peacekeepers may be considered a war crime.

The statement also expressed concern about the security situation in Mali and recent reports of ceasefire violations and called on all parties to fully implement the agreement.

Mali authorities blamed Islamic militants for the attack on a U.N. peacekeeping convoy on Sunday.

Northern Mali was occupied in 2012 by al-Qaida-linked groups before being forced from power by a French-led military operation the following year.