Burundi's president says his government has arrested several suspects in the massacre of 36 people at a Gatumba pub, after he had vowed the case would be solved within a month.

In an exclusive interview with VOA in Washington on Wednesday, President Pierre Nkurunziza said a team of judges is continuing to investigate the September 18 attack.

The assailants burst into the pub, ordered patrons to the ground, and began shooting.

Mr. Nkurunziza did not indicate who was behind the violence. He has previously said the attackers were believed to have crossed the Congolese border about five kilometers from Gatumba.

President Nkurunziza also defended his government's efforts to curb violence, saying the security situation has improved since he took office in 2005.

He said illegal arms continue to be a problem in the Democratic Republic of Congo, and he said at least 80,000 weapons have been taken from civilians.

Burundi has been relatively peaceful since its last rebel army, the Forces for National Liberation , laid down its arms in 2009 after 20 years of insurgency. But recurring attacks have raised fears of a return to conflict.

Congolese officials have suggested the Gatumba attackers were more likely former FNL rebels and not from eastern Congo.