If the offer was refused, however, the Mongols would invade and destroy the city or town, but allow a few civilians to flee and spread terror by reporting their loss. These reports were an essential tool to incite fear in others. However, both sides often had a similar if differently motivated interest in overstating the enormity of the reported events: the Mongols' reputation would increase and the townspeople could use their reports of terror to raise an army. For that reason, specific data (e.g. casualty figures) given in contemporary sources needs to be evaluated carefully.