Niamey, Mar 23 (IANS): The death toll in an attack by armed assailants on several villages in Niger near the border with Mali has increased to 137, according to a government spokesperson.

The villages in the Tahoua region were overrun on Sunday by unknown assailants, reports dpa news agency.

An earlier tally had placed the number of dead at 40.

The government spokesperson, Abdoulraman Zakaria, said that soldiers were sent to the region and had fought the attackers.

Numerous armed groups are active in Niger and in neighbouring Sahel countries.

Some have sworn allegiance to the Islamic State terror group, while others are linked to the Al Qaeda.

The government has little control over the desert areas outside the cities, a situation which is exploited by jihadist groups and criminal networks such as people smugglers.

In the Mali border region there have been recurring attacks.

Only a week ago, at least 58 people were killed in an attack on market traders in the region of Tillaberi, the government said.