Human Rights Watch (HRW) has claimed that cluster munitions have been used in Libya, Sudan, Syria, Ukraine, and Yemen this year, causing unacceptable harm to civilians.
In a recently published report, 'Cluster Munition Monitor 2015', the watchdog noted that cluster munitions have been used in seven countries since 2010, including five this year.
Thailand and one or more members of a Saudi Arabia-led coalition bombing rebels in Yemen are accused of using the weapons in February 2011 and March this year, respectively.
However, the report does not document any new use of cluster munitions by any of the state parties to the 2008 Convention on Cluster Munitions, since it entered into force on 1 August 2010.
The Convention on Cluster Munitions bans use, production, transfer, and stockpiling of cluster munitions due to their widespread indiscriminate effect at the time of use, and the long-lasting danger to civilians.
The treaty also requires the clearance of cluster munition remnants within ten years, as well as assistance for victims of the weapons.
Human Rights Watch arms division advocacy director and the report editor Mary Wareham said: "The new use of cluster munitions has elicited a strong reaction from other countries, indicating that the stigma against these weapons continues to build as the treaty's ban takes hold.
"Countries that care about protecting civilians should condemn any use of cluster munitions and put pressure on users to abide by and join the convention."
A total of 95 states parties are legally bound to carry out all of the convention's provisions, while another 22 have signed but are yet to ratify the convention.
According to the report, the states parties have destroyed a total of 1.3 million stockpiled cluster munitions containing 160 million submunitions, which represents the destruction of 88% of all cluster munitions and 90% of all submunitions declared as stockpiled by them.
Fired by artillery and rocket systems or dropped by aircraft, the cluster munitions typically explode in the air and send dozens of smaller bomblets or submunitions over a large area, which often fail to explode on initial impact, leaving duds. The duds act like landmines and pose a threat until cleared and destroyed.
Image: 9N235 submunitions that failed to explode during a cluster munition attack collected and displayed in Starobesheve, Ukraine. Photo: © 2014 Human Rights Watch.