President Pierre Nkurunziza’s candidacy for a third term provoked months of protests in Burundi.
The opposition termed it unconstitutional while the international community condemned it.
Nkurunziza was, however, declared the outright winner of the controversial election on July 24.
He is to be sworn in by mid-August after the first sitting of the Senate on August 12.
An unknown armed group is said to be responsible for the assaults.
After the disputed presidential election in Burundi, that was widely criticised by the international community, violence has been rising in Bujumbura, particularly at night. Government officials, civil society organisations and opposition members are all being attacked by an unknown armed group.
For example, on August 2, Adolph Nshimirimana, a former army chief of staff and intelligence chief, was killed in the capital. The attackers reportedly targeted his car with machine guns and rocket launchers.
Gen Nshimirimana’s death was seen as a major blow to President Pierre Nkurunziza as he played a critical role in foiling the May 13 coup d’état led by the former intelligence chief Gen Godefroid Niyombare.
“Urgent investigations should be conducted into the killing of Gen Nshimirimana, and within one week we should be able to bring the perpetrators to justice,” said President Nkurunziza.
Pierre Claver Mbonimpa, the chairman of the Burundian Association for the Protection of Human Rights and Detainees, was also recently injured when armed gunmen shot at him on his way back home.
Mr Mbonimpa openly opposed President Nkurunziza’s bid to run for a third term, and played a crucial role in organising protests. Those opposed to the incumbent’s third term said it violated the country’s Constitution and the 2000 Arusha Peace and Reconciliation Agreement for Burundi, which limit a president’s tenure to two terms.
African Union chairperson Dr Nkosazana Dlamini Zuma called on the Burundian government to investigate the killing of the former close aide of President Nkurunziza, and the attempted murder of the human rights activist.
Less than 24 hours after the attack on Mr Mbonimpa, the head of the security at the national broadcaster, Lt Col Dismas Indaye, was shot by unknown armed men riding in a car.
Pierre Nkurikiye, the deputy police spokesman, told The EastAfrican that two civilians were kidnapped and killed Wednesday night by an unknown armed group in Buterere.
“The same night, two armed men were killed in Cibitoke after they attacked a police patrol van,” he said.
According to the government, an unknown group of armed people dressed in army uniform are responsible for the attacks, and are sometimes mistaken for the army.
“We call on the Burundian police and army to control and be vigilante about those unknown group of people who seem to hide in army uniforms,” said a statement read from the Ministry of Public Security.
But security officers are finding it difficult to stop the attacks in Mutakura and Cibitoke suburbs in Bujumbura, which have been hotspots for protests since April.
A soldier in Mutakura said the area is becoming a stronghold of the armed militias.
“Armed youth keep exchanging rounds of gunfire at night with the police; it is really worrying as administrators have fled,” he said.
Nkundwanayo Audace, a resident of Mutakura, said the armed youth emerge at night and block the main roads, making it impossible for both the police and the army to pass.”
“We don’t know where these armed youth come from; they emerge late in the evening,” he said.
Meanwhile, Human Rights Watch is raising the alarm over rights abuses, saying that Burundian intelligence officials, police and the ruling CNDD-FDD youth wing (Imbonerakure) militia have arbitrarily arrested and mistreated scores of people suspected opposing the government. HRW said it had documented 148 cases between April and July in four provinces and in the capital.
“Imbonerakure have no legal right to arrest anyone, yet they have been stopping people arbitrarily, beating them and handing them over to the intelligence services who have tortured some of them,” said Daniel Bekele, Africa director at Human Rights Watch.
More than 170,000 Burundians have fled to neighbouring countries for fear of their lives ever since protests broke out in the country over President Nkurunziza’s third term.
The incumbent has been at the helm since 2005.The country’s constitutional court this week validated his win in last month’s presidential election.