Dozens of delegates to an international conference on the Convention on Cluster Munitions have expressed concern over the use of the lethal weapons, including in the battlefields in Ukraine.

A meeting of state parties to the convention began on Monday in Geneva, Switzerland. Cluster munitions disperse small bomblets, which can fail to explode and pose a prolonged risk to civilians.

The Convention on Cluster Munitions bans the production, stockpiling, use and transfer of the weapons. It has been joined by more than 110 states, including Japan.

An official from the European Union voiced deep concern over the increasing number of victims produced by the extensive use of the munitions in Ukraine, Syria, Yemen and other areas.

A delegate from Colombia expressed regret that the transfer and use of cluster munitions are undermining global efforts to eliminate the threat posed by the weapons.

An international NGO and others say the number of people killed or wounded by cluster munitions surged to nearly 1,200 around the world last year. They say most of the casualties were in Ukraine.

Russia, which has not signed the convention, has been using cluster bombs in Ukraine. Ukrainian forces are also using the munitions provided by the United States.

Delegates plan to discuss how countries are proceeding with their disposal of cluster bombs, and what assistance they may need. They plan to adopt a report to wrap up the conference on Thursday.