Submunitions in Syria: understanding the threat

As part of an ongoing effort to raise awareness of the threat of UXO in Syria, I have recently designed two information sheets on the two varieties of cluster bomb submunitions identified in Syria to date. These are being published under the auspices of the Responsible Researchers of Munitions & Arms (RRMA), a group of which I am a proud founding member. It is our aim to contribute accurate and timely information about arms and ordnance safety, identification, and tracing which is relevant to current conflicts.

The text of this information sheet reads:

PTAB-2.5M (Protivo Tankovaya Avia Bomba Modernizirovanii; Anti-Tank Aviation Bomb, Modernised) and AO-1SCh (Aviatsionnaya Oskolochnaya; Aviation Fragmentation Bomb) submunitions have both been identified in Syria. Both of these munitions are deployed from RBK (Razovaya Bombovaya Kasseta; Single-Use Cassette Bomb) family cluster bombs, such as the RBK-250-275 and the RBK-500. In the typical configuration seen in Syria, each cluster bomb would be capable of distributing either 150 AO-1Sch (RBK-250-275) submunitions, or 42 PTAB-2.5M submunitions (RBK-250).

The duplex detonator of the AO-1SCh utilises mercury fulminate to detonate the primary explosive charge of the submunition. Mercury fulminate degrades significantly over time, rendering it more insensitive to impact. As a result, the chance of successful detonation decreases over time, resulting in a much higher dud rate for old munitions. Most of the AO-1SCh examples seen in Syria have dated from the 1970s. Improper deployment of the munitions (i.e. incorrect ejection height or speed) as a result of poor or inadequate training may also play a role in the large number of unexploded submunitions observed.

These munitions, both produced in the former Soviet Union, pose a considerable risk to the civilian populace within Syria. All unexploded ordnance (UXO) should be treated as live, and avoided where possible. UXO such as these submunitions are particularly hazardous, and should not be handled under any circumstances.

The PDF version of this information sheet can be downloaded here.

A simpler version of this sheet, ideal for printing at home and distributing at rallies or demonstrations, can be downloaded here.

I would like to thank Ivan Kochin, Alex Diehl, and Mark Hiznay for their feedback. Images of submunitions provided above are courtesy of Free Taftanaz.

As always, if you see UXO, remember the ‘ARMS’ acronym:

AVOID the area
RECORD all relevant information from a safe distance
MARK the area to warn others
SEEK assistance from the relevant authorities


  1. […] burning. This ignition process remains reasonably reliable over time, unlike the fuzes seen in some other cluster bomb submunitions identified in Syria, such as the AO-1SCh, however dud munitions are still likely. Incorrect employment of the […]

  2. Mike Weber · · Reply

    what has not been seen yet, are the submunitions that are delievered from Frog7, SS21 and Ss26 missile systems. Plus submunitions delived from projectiles. Both of these systems are known to have been used, but appears no one has seen or noted them as of yet

    1. I have some limited info on these, which I will send you, but no images. Certainly interesting!

  3. This is a damn good idea I hope to see more of them.

    Not to be picky, but is there an Arabic or other non english versions of this available? I only ask since I believe Syria is 90% Arabic speaking.

    1. David,

      We would love to get these up in other languages, however RRMA is an informal organisation without funding. We’re looking into this possibility at the moment.

  4. Hey guys,

    Really appreciate the work you are doing on categorizing these submunitions and the systems that deploy them. Currently my team is creating an infographic (which should be ready for soft release in a week) which will compile all this information and more. I work with the news agency Syria Direct ( which operates out of Jordan and has reported previously on the weapons utilized by both the Syrian Army and the Rebels ( We should have an arabic translation of the infographic as well when it is ready for release. I would love to establish some contact between our aligned interests so please feel free to contact me at


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