Cobbles were brought into the city to block and limit access and exit from the town; the perpetrators had previously obtained the list of addresses of the Armenian residents of the city. Warnings by Azerbaijanis sympathetic to their Armenian neighbors instructed them to leave their lights on the night of the 27th; those who shut them off would be assumed to be Armenian. According to several Armenian witnesses and Soviet military personnel, alcohol and "anasha", a term referring to narcotics, were brought in trucks and distributed to the crowds, although such accounts were not reported in the media. According to de Waal, the fact that the attackers were armed with homemade weapons that would have taken some time and effort to manufacture suggests a certain level of planning.