The Burundi’s environment minister, Emmanuel Niyonkuru, has been shot dead while on his way home on New Year’s Eve.

The 54 year old man was killed at about 00:45 local time (22:45 GMT) by “a criminal with a gun”, a police spokesman tweeted.

Tweets from Pierre Nkurikiye reveal that a woman who was with Mr Niyonkuru had been detained for questioning, following the “assassination”.

Burundi’s President Pierre Nkurunziza has promised that the crime would not go unpunished.

Since the President’s aspiration for a third term in office in 2015, there has been an unrest in the country leading to the death of hundreds of people, including high-ranking army officials. Notwithstanding,  Burundi has been relatively calm for months, BBC reports.