OUAGADOUGOU (Reuters) - Burkina Faso’s parliament has voted to provide funding and training to local vigilantes in response to the growing firepower of jihadist groups who threaten to overrun government forces across large swathes of the West African country.

The move, which is expected to apply mostly to vigilante groups called koglweogo - “guardians of the bush” in the Moore language - has drawn concerns from the United Nations and human rights activists, who fear it could empower fighters accused of ethnic killings in the past.

The vigilantes grew significantly as a response to instability that followed the 2014 revolution that overthrew longtime President Blaise Compaore. There are an estimated 40,000 such groups across Burkina Faso, according to the U.N.

“This law was voted unanimously by the parliament,” Defence Minister Moumina Cheriff Sy told reporters after the vote late on Tuesday. “It shows that beyond our differences of opinion... we can be one when it comes to defending the homeland.”

Security deteriorated dramatically across Burkina Faso and its neighbors in the semi-arid Sahel region last year, as Islamist militants with ties to Islamic State and al Qaeda stepped up their attacks.

On Monday, militants killed 36 people at a market in a village in northern Burkina Faso.

Collaboration between state security forces and the vigilantes has previously been informal. The government said the new law would help defeat the “terrorist Hydra”.

The law, which now goes to President Roch Marc Kabore for his signature, calls for volunteers to receive brief military training, unspecified equipment, healthcare and bonus payments. Recruitment is to be managed by village leaders.

A U.N. committee of experts on torture voiced concerns in November about a lack of oversight of the koglweogo, saying the groups were implicated in a massacre of dozens of Fulani herders in January 2019.

The jihadist violence in the Sahel has also fueled ethnic conflict, particularly between rival hunting and farming communities, with ethnic self-defense militias targeting civilians in reprisal for militant attacks.

In neighboring Mali, a vigilante group is believed to be responsible for an attack that killed about 160 Fulani civilians last March, the deadliest such incident in recent times.