Three Tanzanian peacekeepers were injured Thursday when their vehicle struck an explosive device in the western part of the Central African Republic, according to the local UN mission, MINUSCA.

In recent months, the long-running conflict between rebels and government forces has switched gears, with armed groups driven out of the main cities increasingly resorting to guerrilla tactics, including laying mines.

While roadside explosives have previously ground humanitarian work to a halt in the northwest of the country, mines are less common in the west.

On Thursday morning, the peacekeepers’ convoy was leaving the town of Berberati — about 500 kilometres (300 miles) from the capital — for a temporary military outpost when it drove over a mine, according to MINUSCA.

One severely injured peacekeeper was transported to Bangui for treatment.

“This is the third time that MINUSCA peacekeepers have fallen victim to explosive devices in the Central African Republic,” the UN mission said in a statement.

After several years of a simmering continuation of the civil war that erupted in 2013, recent months have seen a spike in violence.

The mostly sectarian unrest in the country of almost five million people, which the UN ranks as the world’s second least developed, has displaced hundreds of thousands and spawned a major humanitarian crisis.

President Faustin-Archange Touadera, who was re-elected in a vote late last year, declared a unilateral ceasefire in October and his government claims to have recaptured 90 percent of the nation’s territory.

But widespread insecurity, and a swelling food crisis, persists, especially in the northwest.

Since August, mines have killed eight people, including two women and a five-year-old child, in the northwest, according to MINUSCA.