Three UN troops were killed and four more wounded when their convoy hit a roadside bomb early Sunday, officials said, in the latest violence to hit the war-torn West African state.

Chadian peacekeepers were on a routine patrol in Aguelhok commune in the north of the country, the UN peacekeeping mission in Mali, known as MINUSMA, said in a statement.

Three soldiers were killed and four were seriously wounded in the blast, it added.

"We will have to make every effort to identify and apprehend those responsible for these terrorist acts so that they can be brought to justice," said MINUSMA mission head Mahamat Saleh Annadif.

"I bow before the remains of these brave blue helmets who died in the service of peace in Mali".

The UN mission has some 13,000 troops drawn from several nations deployed across the vast semi-arid country.

Mali is struggling to contain an Islamist insurgency that erupted in 2012 and which has claimed thousands of military and civilian lives since.

Despite the presence of thousands of French and UN troops, the conflict has engulfed the centre of the country and spread to neighbouring Burkina Faso and Niger.

Laying roadside bombs is a favoured tactic of jihadists active in the Sahel.

Also known as improvised explosive devices, they kill and maim scores of victims every year in Mali.