1)
Fuze systems of all kinds that include detonators - especially
mortar fuzes.
2)
Grenades of all types (including many that are still 'pinned').
Most found have been from the former USSR. Some have no time
delay. Technically those still pinned are not UXO, but are
ERW.
3) Improvised explosive hazards (also called IEDs), some of which may have multiple fuzes and are very hard to locate in post-conflict urban debris.
4)
40mm rifle grenades, various origins. These may also have
a self-destruct delay - which can fail to complete, so leaving the item potentially very sensitive.
5)
DPICM (UK, USA, Yugoslavia - variations in other countries).
The Yugoslav KB-1 variant has been identified as especially
dangerous but the M42 has featured in more accidents.
6)
BLU-97 (USA) Multi-directional secondary fuze system that
can remain operational and act as an anti-handling device.
Extremely high failure rates have been reported.
7) Any cluster munition dispersed in an ammunition storage accident.
8)
BL-755 (UK) used by 17 countries, 8 NATO and 9 others: considered
very unpredictable when unexploded.
9)
M118 Rockeye (USA) an extremely high failure rate is reported.
10)
PG-7M (Russian) despite the fact that some are supposed to have a
self destruct, these are frequently found in an unstable condition
- presumably because they have a piezoelectric fuse.
11)
60 - 120mm mortars, HE and WP, various origins - usually initiated
by deliberate contact (taking apart).
12
Anti-armour hand grenades (often based on the Russian RKG-3
series).
13)
HE rockets damaged on impact. (In all cases, risk may be increased
if the munition is damaged.)
a) What percentage
of each type of munition can be later initiated accidentally?
(For example, for every 100 of a type, some may be 'dud' and some
may be very sensitive to movement. The specific fuze system
is often the critical factor when assessing the risk
of accidental initiation. The first seven can certainly be initiated accidentally during demining, but that says nothing about the percentage that could not have been.
b)
What proportion of civilian accidents occur as a result of
a deliberate interaction with the device? In these cases,
the fuze system may be relatively unimportant. From my own experience around the world, after displaced people have returned to their homes and suffered from any mines, booby traps or IEDs left there, the majority of civilian accidents involve a deliberate interaction with a found device. Too many others occur when digging or ploughing on land that has supposedly been searched and cleared - but these accidents often involve mines so are not helping to answer the original question.