NEW : `` To be fair , when we look back , we can understand that our guns scared them , '' said one of the men , Ove Oberg , who met with CNN Monday morning . U.N. secretary-general is `` extremely concerned '' about ongoing clashes . Police used tear gas on demonstrators Monday in Tunis . Comment: Weeks of demonstrations have left 78 dead and has cost billions , the government says .
NEW : U.N. secretary-general is `` extremely concerned '' about ongoing clashes . Police used tear gas on demonstrators Monday in Tunis . Comment: Weeks of demonstrations have left 78 dead and has cost billions , the government says .