Nairobi , Kenya ( CNN ) -- In the village of Angolo , in Sudan 's South Kordofan state , villagers stand over a deadly and illegal weapon . Nestled in a crater , the Soviet-era cluster bomb failed to detonate . It was dropped a month ago , they say , and they do n't dare get any closer . Across rocky outcrops , tennis ball-sized bomblets spilled out of the RBK-500 model bomb and scattered everywhere . Each of them is highly volatile and easily capable of blowing off a limb , or worse . The footage , obtained and verified by CNN , is damning new evidence that the Sudanese government is using cluster munitions in civilian areas . `` Cluster bombs are known to be indiscriminate and unreliable weapons . This is why they have been banned by international law , '' said Laura Cheeseman , the director of the Cluster Munition Coalition . `` It is the humanitarian impact of these weapons that makes it so atrocious that Sudan has used them . '' The villagers in this part of South Kordofan say they live in fear of the bombing raids by Sudanese airplanes that seem to happen almost daily . `` Today they bombed with their airplanes . They bombed up there in the mountains and they bombed close to here . Today , '' an Angolo resident said . Civilians in the Nuba Mountains have resorted to hiding in rocky outcrops and caves , and piling stones over makeshift foxholes to take cover from the bombing raids . And cluster bombs present an even greater threat than regular munitions , rights groups say . `` Cluster munitions contain dozens or sometimes hundreds of explosive bomblets , so when they 're used , they scatter over a very large area , often the size of several football fields , '' Cheeseman said . Anyone in the strike zone can be killed . And often , the greatest threat comes after the bombs are dropped . About 10 % of bomblets in modern cluster weapons usually fail , weapons experts say . But with older munitions like the RBK-500 , that percentage can be much higher . The cluster bomblets become a minefield . And while mines are dangerous because they are invisible , volatile cluster bombs are deadly because they lie in plain sight . Often , they attract children . `` [ The bombs ] can land in fields , in homes , in villages , and of course it poses a risk to civilians , '' said Klaus Ljoerring Pedersen , regional director of the Danish Demining Group , a humanitarian organization that helps solve problems related to leftover ordnance . `` Civilians do not recognize what is a bomblet -- dangerous and highly explosive -- and what is a toy . So you see a lot of curious children after these raids go out and identify these new and exiting objects and blow their hands and heads off . '' Sudan is fighting a bitter conflict against the SPLA-North , a rebel group that wants to be part of independent South Sudan . The rebels depend on local villages for food . The Sudanese military strategy seems clear : It aims to terrify and starve the civilians into leaving the area . It appears to be working . Thousands of villagers have fled to camps like Yida , where humanitarian agencies have struggled to feed and shelter them . The U.N. refugee agency says more than 500 arrive every day . This latest evidence of cluster munitions in South Kordofan suggests that the Sudanese military is stepping up its campaign , but a Sudanese army spokesman flatly denied that they use cluster munitions . `` We do n't use cluster munitions in South Kordofan , we have no ties to such weapons , '' military spokesman Al-Sawarmi Khalid told CNN . `` There is no need to use these kinds of weapons to begin with , the fighting is in open space , the renegades do n't have concrete fortifications . '' Khalid added that the footage could have been taken anywhere . But CNN knows that the footage was taken in Angolo village . And this would n't be the first time that Sudan has been accused of dropping the highly controversial weapons . The Danish Demining Group says that it still finds Chilean-made PM-1 bomblets throughout South Sudan , particularly in the areas between Juba , the capital , and the Ugandan border . The munitions were dropped during the long civil war between the North and South that ended in 2005 . Military analysis and logic suggests that since the SPLA in the South had no significant airpower , and they were unlikely to drop bombs on themselves , the cluster munitions came from Sudanese warplanes . Sudan has frequently denied ever using cluster munitions and has not signed the convention to ban the weapon . The country has promised to sign up `` as soon as possible . '' Since 2008 , more than 100 nations have signed the convention . `` It 's not surprising in a way that Sudan denies the use of these weapons , even though they are so stigmatized and rejected by the international community . No country wants to be associated with these weapons , whether they 've signed onto the ban or not , '' Cheeseman said .
Cluster munitions scatter bomblets that can be especially dangerous to civilians . International law permits such bombs , but Sudan has yet to sign on . Civilians in Sudan 's South Kordofan state say planes have used them . A spokesman said that the Sudanese army uses cluster munitions .