A package that officials said contained two vials of a "homemade explosive substance" was discovered near the Arizona State Capitol in downtown Phoenix on Monday.
A suspicious package was discovered in Sherman Oaks, prompting the evacuations of several businesses and a response from the LAPD bomb squad.
A portion of the northbound 5 Freeway in Burbank was temporarily shut down as a bomb squad investigated a backpack emitting smoke on an overpass.
A series of threatening letters containing a mysterious white powder is raising concerns that Republican lawmakers in Kansas are being targeted.
Since Friday, about 100 letters have been received by Kansas GOP lawmakers and Kansas Attorney General Kris Kobach, who is also a Republican, officials said.
The number more than triples the amount when the situation was first reported early Friday evening.