Why does this script not function properly?

The script I've written is supposed to check if the part "mine" exists, and if it doesn't, create a new one. The problem is that for some reason, when the new mine is created, it will infinitely explode, even when a player is not touching it. Why is this?

part = game.Workspace.mine

while true do
if game.Workspace:FindFirstChild("mine") then
	print("the mine is okay") else
	function createmine()
		local mine = Instance.new("Part")
		mine.Name = "mine"
		mine.Parent = workspace
		mine.Position = game.Workspace:FindFirstChild("master").Position
		mine.Size = game.Workspace:FindFirstChild("master").Size
		local function OnTouched()
			local expl = Instance.new("Explosion")
			expl.Parent = mine
			expl.Position = mine.Position
			wait(1)
			mine:Remove()
		end
		mine.Touched:connect(OnTouched)
	end
	createmine()
end

wait(3)



function OnTouched()
	local expl = Instance.new("Explosion")
	expl.Parent = part
	expl.Position = expl.Parent.Position
	wait(1)
	part:Remove()
end

part.Touched:connect(OnTouched)

end

Put your functions and event outside of the while loop.

part = nil -- Setting an empty variable for now

if game.Workspace:FindFirstChild("mine") then
	part = game.Workspace.mine
end

function createmine()
	local mine = Instance.new("Part")
	mine.Name = "mine"
	mine.Parent = game.Workspace
	master = game.Workspace:FindFirstChild("master")
	mine.Position = master.Position
	mine.Size = master.Size
	part = mine
end

while wait(3) do
	if part then
		print("The mine is okay")
	else
		createmine()
	end
end

partCoroutine = coroutine.resume(coroutine.create(function()
	while part do
		part.Touched:connect(function()
			local expl = Instance.new("Explosion")
			expl.Parent = part
			expl.Position = part.Position
			wait(1)
			part:Remove()
			part = nil
		end)
	wait()
	end
end))