Nigeria’s President Bola Tinubu has ordered the army to arrest the killers of 16 soldiers who were murdered while on a peace mission in the south of the country last week.

The troops were responding to clashes between the Okuama and Okoloba communities in the oil-rich southern Delta state, when they were attacked by some community youth, the army said in a statement.

President Tinubu said a civilian was killed in what he termed “a direct attack on our nation”.

“The cowardly offenders responsible for this heinous crime will not go unpunished,” the president said.

“The defence headquarters and chief of defence staff have been granted full authority to bring to justice anybody found to have been responsible for this unconscionable crime against the Nigerian people,” he added.

Nigeria’s military said on Saturday that an investigation was underway and several arrests had been made in connection with the killing of a commanding officer, two majors, one captain and 12 soldiers during the attack.

Earlier on Sunday, reports said parts of the community were set ablaze by unknown groups while the villagers fled the area for fear of reprisal attacks by the country’s military.

Army spokesperson Brig GenTukur Gusau told the BBC he was unaware of the latest incident. However, he emphasised that “the military must retrieve the arms and weapons taken from the slain soldiers.”

Rival communities have clashed repeatedly over land ownership and fishing rights in recent weeks, leaving several people dead, local media reported.