A grenade attack on a military base in Burundi’s capital killed a child and wounded his father and one other person, an official and witnesses said on Sunday, as violence linked to the president’s disputed re-election persists.

More than 400 people have been killed since April last year when President Pierre Nkurunziza announced he would run for a third term. That sparked weeks of street protests led by the opposition which said his bid was unconstitutional.

Witnesses and an official said the attack late on Saturday had targeted the base in the Ngagara neighbourhood in Bujumbura.

“The attackers were in a car and threw two grenades at a military station which injured two people including a child and his father, both coming from a hair salon,” a Ngagara administrator on Sunday.

“The child died after but his father is undergoing treatment,” he said.

A witness who gave his name only as Paul, 33, said a soldier was also wounded, but the administrator could not confirm it.

It was not immediately clear who was responsible, but activists and authorities have in the past reported a number of apparently targeted killings.

On Friday, unidentified gunmen shot dead two people in an apparent targeted killing the Gisozi commune in Mwaro province some 60 km (37 miles) from Bujumbura.

According to the U.N. refugee agency UNHCR, nearly quarter of a million people have fled the violence in Burundi, which emerged from an ethnically charged civil war ten years ago.

In December, the African Union’s (AU) Peace and Security Council announced plans to deploy a 5,000-strong force, saying it could invoke an article of the AU’s charter that allowed it to intervene whether or not the government agreed.

Last week, the AU said it had appointed five heads of state to try to convince the government of Burundi to accept the peacekeeping force.

Nkurunziza, whose army foiled an attempted coup in May, is steadfastly opposed to the plan, saying its deployment would amount to an invasion.