The problem started last week when I started receiving Cell Broadcast alerts non stop all day. My phone is Samsung Galaxy S2 and was running on latest version of Cynogenmod. After searching in some Android forums I found a way to disable all kinds of cell broadcast by using option in Message application.
Even after doing so the problem did not go away. Finally after lot of searching I found a way to disable CellBroadcast in Cyanogenmod. Use Terminal Emulator and execute the following commands.
su mount -orw,remount /system rm /system/app/CellBroadcastingReceiver.apk reboot