Casualties from land mines and similar booby-trap explosives increased for the second consecutive year in 2016, to the highest level since a treaty banning such weapons of war took effect in 1999, a monitoring group said Thursday.

The group, the International Campaign to Ban Landmines, attributed the increased casualties largely to armed conflicts in Afghanistan, Libya, Ukraine and Yemen.

For 2016, the group recorded 8,605 casualties from land mines, including improvised devices triggered in the same way, as well as from other explosive remnants of war that are inadvertently detonated, often by unsuspecting civilians. The 2015 casualty figure was 6,461.

The figures include deaths and injuries, many of them suffered by children. The total in 2016 was the highest since the 9,228 casualties recorded 18 years ago when the land mine treaty first came into force.