UNITED NATIONS, May 9 (Xinhua) -- UN Secretary-General Antonio Guterres on Tuesday strongly condemned an attack which killed four blue helmets in the southeastern part of the Central African Republic, calling for efforts to "swiftly bring those responsible to justice."

Eight other peacekeepers were wounded in the attack perpetrated on Monday by suspected anti-Balaka against a convoy of the United Nations Multidimensional Integrated Stabilization Mission in the Central African Republic (MINUSCA) on the Rafai-Bangassou axis. And one is still missing.

"The secretary-general would like to underline that attacks against United Nations peacekeepers may constitute a war crime," said a statement issued here by Guterres' spokesman. "He calls on the Central African Republic authorities to investigate the attack in order to swiftly bring those responsible to justice."

The secretary-general would like to reiterate his support for the actions of MINUSCA to protect civilians and stabilize the republic, and call on all parties to heed President Faustin Archange Touadera's call to cease violence and work together for the country's stability, the statement said.

"MINUSCA vigorously denounces this odious attack on peacekeepers whose presence on the Central African soil has no other objective than to help the country to protect its population and to allow the Central African Republic to emerge from the cycle of violence caused by armed groups," said a press release.

The mission added that it would do everything possible to ensure that perpetrators of the attack, who fled into the bush, are arrested so that they can be brought to justice.

Despite significant progress and successful elections, the Central African Republic still suffers instability and sporadic unrest.

Clashes between the mainly Muslim Seleka rebel coalition and anti-Balaka militia, mostly Christian, plunged the country of 4.5 million people into civil conflict in 2013.