How do i call an Activity from a broadcast receiver class

I'm working on an alarm app and I have created a custom broadcast receiver class, the problem is in the onReceive() when a start a new activity with Intent the app crashes with this error:

AlarmReceiver: android.util.AndroidRuntimeException: Calling startActivity() from outside of an Activity  context requires the FLAG_ACTIVITY_NEW_TASK flag. Is this really what you want?

where am I going wrong please help me