The death toll from Tuesday's ambush on Nigerien troops near the border with Mali has risen to 28, an army spokesman and security sources have said, as ISIL claimed responsibility for the attack, reported aljazeera.com.

An army spokesman on Thursday confirmed the toll has risen to 28.

Later on Thursday, Islamic State of Iraq and the Levant (ISIL, also known as ISIS) claimed responsibility for the attack vie its propaganda media outlet, without providing evidence.

The attack on the military patrol took place near the town of Tongo Tongo, in the western Tillaberi region of Niger.

Armed groups, including affiliates of al-Qaeda and ISIL, have stepped up attacks on military and civilian targets across West Africa's Sahel region this year.

The border areas, where Niger, Burkina Faso and Mali meet, are especially dangerous and violence is worsening across the region.

Attackers killed at least 10 in apparently sectarian attacks on churches in neighbouring Burkina Faso this week. 

Niger also faces a threat in its southeast from Boko Haram and a splinter group affiliated with ISIL, which are both based in Nigeria but frequently carry out attacks in Niger, Chad and Cameroon.