On the other hand, the use of cluster bombs on civilians (e.g. bombing of a marketplace in Nis and couple of bombing of refugee columns, train, buses, bridges with people) can be clearly considered war crimes, breach of war methods. As it was said before, there was obstruction of the research of these topics from the west-leaning government in order not to offend their partners in other countries. Researchers trying to perform a study were reported that they were visited by the personnel of NATO mission in Serbia or Bosnia and were asked what they are doing. They reported different kinds of pressures not to publish these studies.