Geneva (dpa) - Some 220,000 children are at risk of being killed or maimed by military explosives in eastern Ukraine, one of the worldlsquo;s most mine-contaminated areas, the UN Childrenlsquo;s Fund (UNICEF) said Thursday in Geneva.Since January, landmines and unexploded munitions have led to one child casualty every week on average along the 500-kilometre-long strip where Ukrainian government forces face off against Russia-backed separatists.In total, 220,000 children live in this 30-kilometre-wide zone."All parties to the conflict must immediately end the use of these gruesome weapons that have contaminated communities and put children in constant danger of injury and death," said UNICEFlsquo;s Ukraine representative, Giovanna Barberis.Most explosive accidents involving Ukrainian children occur when they pick up objects such as hand grenades or fuses.Across the globe, around 40 per cent of the victims of mines and other war remnants are children, according to the International Campaign to Ban Landmines, which collects global data on this issue.UNICEFlsquo;s call to both sides of the conflict came amid a worsening security situation in eastern Ukraine.Ukrainian President Petro Poroshenko ordered additional troop deployments in the east on Wednesday, after separatists had attacked army positions with multiple rocket launchers in recent days.Poroshenkolsquo;s announcement came despite a Christmas truce that has been agreed to start on Saturday.However, more than a dozen ceasefires have been agreed and broken during the war that started in 2014 and has claimed 10,000 lives so far.