Diplomatic hostilities between Burundi and Rwanda continue to deepen after Bujumbura accused Kigali of being behind the recent failed assassination attempt of President Pierre Nkurunziza’s top aide.

Rwanda, which maintains it has kept its distance from Burundi’s affairs, termed the accusations as mere digressions by Bujumbura to divert attention from the humanitarian and political state the country is in.

The Rwandan army spokesman, Lt Col René Ngendahimana, challenged the Burundian authorities to provide evidence that Kigali was involved in the Monday night ambush of Willy Nyamitwe, the president’s communication advisor.

Mr Nyamitwe came under attack by armed men on November 28 while on the way to his Kajaga home, in the outskirts of Bujumbura. One of his bodyguards was killed and his driver wounded while he sustained injuries on the arm.

READ: Nkurunziza's top advisor escapes assassination attempt

“Some of the perpetrators were arrested… among them is a soldier who told us that people who are behind these targetted killings are based in Kigali,” Burundi police spokesman Pierre Nkurikiye told The EastAfrican.

Dismissing the claims, Lt Col Ngendahimana said that this “is not the first time the Burundi government has levelled wild accusations against Rwanda.”

“This is pure propaganda. There is no Rwandan involved, no RDF military personnel involved in that attempt. I actually do challenge those who are saying that to provide any evidence that Rwanda military is involved in this sort of business,” he said.

“Since the political situation unfolded last year, they have always tried to attribute whatever incidences that occur in their country to Rwanda. This is unfortunate but we have observed that pattern.”

Tensions between the two countries snowballed in July last year when President Paul Kagame openly criticised the Burundian government and his counterpart Nkurunziza of seeking a controversial third term – which he won – that resulted in “killing their citizens”.

Over 500 people have been killed and at least 300,000 have fled the country – mainly to Rwanda and Tanzania, since turmoil began in April 2015, while several well-known figures have been assassinated.

Bujumbura accuses Kigali of recruiting, arming and training Burundian refugees-turned-rebels opposed to President Nkuruzinza’s government. Rwanda denies the accusations.

The deteriorating diplomatic ties have led to heightened security on their frontier borders, with Burundi restricting movement of goods and people. There have also been reports of harassment or arrests of Rwandan nationals in Bujumbura.