1 Kings 15:27

15:27 Baasha son of Ahijah, from the tribe of Issachar, conspired against Nadab and assassinated him in Gibbethon, which was in Philistine territory. This happened while Nadab and all the Israelite army were besieging Gibbethon.

1 Kings 16:16

16:16 While deployed there, the army received this report: “Zimri has conspired against the king and assassinated him.” So all Israel made Omri, the commander of the army, king over Israel that very day in the camp.