who was phoning in reports of Walt being back in town?

Question

In the last episode of breaking bad, Skyler gets a call from Marie with warnings of reports that Walt has been sighted in town and is concerned he will come after one of them. She stated all sorts of odd things such as he was going to bomb city Hall and had a manifesto, etc.

Is it ever revealed who is making the calls? Was it Walt? If so, Why? He could easily just slip by unnoticed so no reason to alert the dea if his goal was to spread them thin as Marie mentioned.

I realize Walt's neighbor called in once after he said hi to her, but who made the other calls?

Answer 1

The biggest proof that Walter is in town is that the stolen car from the cold opening was found in the town.

(Marie) That car they thought he stole in New Hampshire, they found it in a Denny's parking lot right on Central.

Since Walter was phoning his son at school and the DEA, the police was alarmed and they were searching for him, which is why the have found the stolen car so fast.

Beside the phone call from Carol to the police, we can only speculate who was doing the calls like Marie does (I would say it doesn't matter since by Walter phone call from New Hampshire and the stolen car in town, it's very sure that he is there for everyone. Beside that it's not clear if it is distraction from Walter):

(Marie) Skyler, we're getting calls from all over town. He's here, he's there, he's going to blow up city hall. [...]

(Skyler) Who's making these calls, him?

(Marie) There are two or three different voices. They're not sure if they're crank calls or people he's put up to it or if they're actual anonymous tips.

My personal guess would be that Walt has set up the calls in order to distract people and maybe he used Badger and Skinny Pete to do so.

Answer 2

Walter was lurking through his old home, the scene where he saw the letters HEISENBERG all over the living room wall. When he left the house again, the old lady, his neighbour, saw him. She was quite shocked and I guess she was the one who called the cops. Also I think the "manifesto" thing was just an innuendo to the Una Bomber. Walt lived off the grid for a while and came back looking like a hobo, more or less like the Una Bomber.