DAKAR, Senegal (AP) — More than 100 civilians were killed in Niger over the weekend by extremists who attacked two villages, as insurgent violence mounts in the West African nation.

The attacks on the western villages of Tchombangou and Zaroumdareye took place on the same day that Niger announced that presidential elections would go to a second round on Feb. 21.

Niger’s Prime Minister Brigi Rafini visited the two villages Sunday.

“We came to provide moral support and present the condolences of the president of the republic, the government and the entire Niger nation,” he said.

The villages in the insecure Tillaberi region were attacked Saturday after residents killed two rebel fighters, local officials said.

The attacks are among the deadliest in Niger and come on the heels of several others, including one by the Islamic State West Africa Province in the Diffa region a few weeks ago in which dozens of people were killed.

Niger and neighboring Burkina Faso and Mali are battling the spread of deadly extremist violence which is displacing large numbers of people, despite the presence of thousands of regional and international troops.

A year ago, extremists staged mass attacks on Niger's military in the Tillaberi region, killing more than 70 in December 2019 and more than 89 in January 2020. The area is also where four U.S. Special Forces soldiers were killed along with five Nigerien colleagues in October 2017.

While no group has claimed responsibility for Saturday’s killings, the Islamic State in the Greater Sahara has been mounting attacks there for some time.

Niger is pressed on all sides by extremist groups and must deal with spillover instability from both Mali and Nigeria. The cross-border conflict has become more deadly as it mixes with local Niger dynamics, according to Judd Devermont, director of the Africa Program at the Center for Strategic and International Studies.

Extremist groups Islamic State in the Greater Sahara and the al-Qaida-linked JNIM have been successful at strategically wiping out local traditional leaders and then inciting attacks between rival ethnic groups or communities, he said.

“They create uncertainty, unrest and disequilibrium that allows them to exploit grievances, intercommunal tensions,” which they then use to make alliances, he said.

The Niger government has been good in what Devermont called “course correction,” and it has done a better job with community involvement than neighboring governments of Mali and Burkina Faso. However, their capacity is limited as extremists from various groups exploit ethnic tensions across the vast country.

“It’s a wide swath in which different groups are operating in Niger, which means that the government has got a huge challenge on their hands,” Devermont said, noting that the incoming government will have a lot to deal with when it eventually takes office.

Niger was largely spared mass atrocities by armed groups and state forces in comparison to Mali and Burkina Faso until 2020, according to research consultancy MENASTREAM which focuses on security and conflict in the Sahel and North Africa.

Niger's upcoming second-round election in February will pave the way for the country’s first democratic handover of power from one elected president to another. Niger has experienced four coups since it became independent from France in 1960.

President Mahamadou Issoufou, who has served two terms, is stepping down.

Former Foreign Minister Mohamed Bazoum of the ruling party will face off with former President Mahamane Ousmane on Feb. 21.

Bazoum on Sunday posted a video to social media expressing his condolences to the victims.

The U.N. Secretary-General Antonio Guterres condemned the attacks and reaffirmed “the solidarity and support of the United Nations to the government and people of Niger in their fight against terrorism, violent extremism and organized crime,” according to a statement from spokesman Stephane Dujarric.

The U.N. Refugee Agency also condemned the twin attacks, saying they forced at least 1,000 to flee, many by foot, in a region already hosting 60,000 Malian refugees, 4,000 people who have fled Burkina Faso and more than 138,000 internally displaced Nigeriens.

“We express our deepest condolences to the families of the victims of these outrageous attacks on peaceful communities,” said the UNHCR’s representative in Niger, Alessandra Morelli. “Communities which are now torn apart by brutality and forced to flee in a region where tens of thousands of people displaced by violence are hosted and hoping to rebuild their lives.”

Niger, Burkina Faso, and Mali in the Sahel are at the epicenter of one of the world’s fastest-growing displacement and protection crises, the refugee agency said.

Nigeria’s President Muhammadu Buhari also condemned the killings, saying “instability in one part of Africa had implications for the security of others,” in a statement from his office in Abuja.

“I am profoundly shocked by the large scale death of innocent people at the hands of these callous militants who have no regard for the sanctity of human life,” he said. “We are facing grave security challenges on account of the evil campaign of indiscriminate violence by terrorists in the Sahel and only united action can help us defeat these vicious enemies of humanity.”