This evening I set my scanner to the MURS band and let it run a couple of hours to see if there was any activity in my area. My antenna is a chimney mounted ham 2m/440MHz J Pole. Between 2300 - 2400 UTC the scanner would stop occasionally on 151.940 megs with a recorded announcement by a female voice repeating "Alert stop one" about 3 - 4 times with each transmission. At times it sounded like "alert stones one." Does anyone have an idea as to what this is? Thanks very much..