( CNN ) -- The United Nations , citing reports of cluster bombs being used by the Ukrainian government , calls the apparent use of such weapons `` extremely alarming . '' Human Rights Watch issued a report Monday that cited `` widespread use of cluster munitions '' by government forces against pro-Russian rebels in southeastern Ukraine in early October . The explosives injured dozens and killed at least six , including civilians as well as an employee of the International Committee of the Red Cross , according to HRW . `` The reports of use of cluster bombs are obviously extremely alarming , '' Stephane Dujarric , spokesman for U.N. Secretary-General Ban Ki-moon , said Tuesday . `` The secretary-general reiterates his call for an end to use of these indiscriminate weapons and the importance of a world free of cluster bombs . '' Cluster munitions are rockets or bombs that hold dozens or hundreds of smaller bombs inside and are designed to discharge over a wide area when they hit the ground , according to HRW . The dispersal area of the armaments inside is often the size of a football field and puts both combatants and civilians at risk . The rockets that do not explode remain active and are a `` life-threatening hazard for civilians long after conflict , '' the U.N. website says . Ukraine 's envoy at the United Nations denounced such reports . The Ukrainian army `` has never used cluster munition at the ATO ( antiterrorist operation ) area in the Eastern Ukraine , '' Yuriy Sergeyev , Ukrainian Ambassador to the United Nations tweeted Tuesday , citing the official Ministry of Defense statement . Investigators surveyed more than a dozen urban and rural locations during a weeklong trip in October during which they looked at dispersal of munitions and documented the unopened , malfunctioned bombs , according to the report . `` Witnesses also told us what it sounded like when the attack happened , that it was multiple smaller explosions which is typical of a cluster munitions attack , instead of single , larger ones , '' said Ole Solvang , senior researcher at Human Rights Watch . The report added that though there is no conclusive evidence , it is likely that anti-government forces are also responsible for cluster munitions attacks . `` I think it is also an occasion to reiterate the ( U.N. secretary-general 's ) call for a political solution for the current crisis in Ukraine , '' said Dujarric . In recent months , the United States and the European Union have placed sanctions against Russia over its `` illegal actions in Ukraine , '' Obama said in September . Kiev and the West accuse Russian President Vladimir Putin of arming and supporting the pro-Russia rebels , and of sending Russian troops into Ukraine over recent months . In 2008 , over 100 countries in the United Nations signed on to ban cluster bombs , according to the U.N. website . Ukraine and Russia did not sign the agreement .
A Red Cross worker was among civilians injured by apparent secondary explosives in Ukraine . A new report cites ` ` widespread '' use of cluster bombs by Ukrainian forces fighting ISIL . A Ukrainian diplomat said his country uses such weapons . Cluster bombs knock out dozens , sometimes hundreds , of secondary explosives .