The death toll from the worst militant attack in Burkina Faso in recent years has risen to 132, the government said on Saturday, after armed assailants laid siege overnight to a village in the northeast.

The attackers struck during the night on Friday, killing residents of the village of Solhan in Yagha province, bordering Niger. They also burned homes and the market, the government said in a statement.

It declared a 72-hour period of national mourning, describing the attackers as terrorists, although no group has claimed responsibility. Another 40 residents were wounded, government spokesperson Ousseni Tamboura later told reporters.

The United Nations said Secretary-General Antonio Guterres was outraged by the attack, whose victims included seven children.

Despite the presence of thousands of UN peacekeepers, attacks by militants linked to Al Qaeda and the Islamic State in West Africa's Sahel region have risen sharply since the start of the year, particularly in Burkina Faso, Mali and Niger, with civilians bearing the brunt.

The violence in Burkina Faso has displaced more than 1.14 million people in just over two years, while the poor, arid country is hosting some 20,000 refugees from neighbouring Mali.

The latest attack pushes the number killed by militants in the Sahel region to over 500 since January, according to Human Rights Watch's West Africa director, Corinne Dufka.

"The dynamic is the jihadists come in, they overpower the civil defence post and engage in collective punishment against the rest of the village — it's a pattern we've seen everywhere this year," Dufka said.

In March, attackers killed 137 people in coordinated raids on villages in southwestern Niger.