Nigerian President Muhammadu Buhari says he is in shock after learning of the death of a military officer and his partner, shot dead and then beheaded in the south-east of the country.
Mr Buhari has ordered that the “perpetrators of the barbaric crime be brought to justice.”
Authorities accused a separatist group, the Indigenous People of Biafra (Ipob) for killing the couple as they travelled for their wedding last weekend.
But the Ipob denied the allegation.
Gunmen in south-east Nigeria have recently stepped up their attacks mostly targeting the security forces.