Short answers, pulled from the story.
An explosive weapon is a weapon that uses an explosive to project blast and fragmentation outward from a point of detonation. They range from hand-held grenades and mortars under 100 mm caliber, classified as light weapons, to aerial bombs and multiple rocket launchers, classified as heavy weapons.
According to Action on Armed Violence, 91 percent of direct casualties when explosive weapons are used in populated areas were civilians, based on data recorded in 2012.
The 1997 Mine Ban Treaty prohibits anti-personnel landmines and the 2008 Convention on Cluster Munitions bans cluster munitions, each for states that are parties to those treaties. The Saint Petersburg Declaration of 1868 bans certain explosive rifle projectiles and has evolved into a customary international humanitarian law prohibition on exploding ammunition binding all states.
Unexploded ordnance, or UXO, is an explosive weapon that failed to detonate as designed and was left behind. Under Amended Protocol II and Protocol V to the United Nations Convention on Certain Conventional Weapons, states that used the weapons must record and share information about their use and assist with removal.
Action on Armed Violence recorded a 70 percent rise in civilians killed or injured by car bombs, suicide bombs, and other improvised explosive devices in the three years leading up to 2013.
The International Network on Explosive Weapons, known as INEW, is a partnership of non-governmental organizations calling for immediate action to prevent human suffering from the use of explosive weapons in populated areas.