@Dušan, I’m glad your grandfather was not hurt. I was reading about the incident you mentioned and the details are sketchy as to the source of the attack(s). International sources do not believe the Croatian national guard was responsible but lend the possibility to independent paramilitary activity though they can’t pinpoint which. Doesn’t seem like a proper investigation was done. Your city of Sid was a heavily militarized one though based on some of the reports at the time and even used as a staging ground for Serb/Yugoslav forces to enter Croatia.  That’s not justifying any shelling but would explain why it made for an enticing target to some unidentified militants. I don’t think its ample evidence to demonstrate that whichever force attacked Sid and Apatin wanted to capture and dominate those areas like other forces attempted to do in Croatia-Slavonia. At the time propaganda (especially media) was hot and heavy on both sides and any reason to blame the other was seized upon depicting the other side in the most unfavorable terms. It’s sad innocent people lost their lives no matter which side it was.