"thoughts were interrupted" is correct and usable in written English.
You could use it when describing a character or speaker who had their thoughts suddenly broken off and changed direction. For example: "Gavin was deep in thought, contemplating an important decision, when his thoughts were interrupted by a loud knock on the door."
His parents had raised him to think, but his thoughts were interrupted once he left Harvard.
A few hours passed quickly, until my thoughts were interrupted by the wailing of French police sirens in the distance.
For a few days, he worried about what he would say, but, when he stood before the campers, his thoughts were interrupted by a reassuring message: "Teach this book, and I will take care of everything else".
"Is there any point to this interview, Martin, or is this just poverty porn?" "Do you have a question, Martin?" "Do you have a question, Martin?" My thoughts were interrupted by the IRP representative I'd been partnered with for this house visit, an American woman whose thousand-watt enthusiasm I rather envied.
My thoughts were interrupted by a dry, metallic sound.
My thoughts were interrupted by my professor's wife: Dessert was ready whenever we were.
Maggie Tulliver's thoughts are interrupted mid-flow by another kind of stream, running cold around her feet, necessitating a long dash on the page and a jolt from quiet mental struggle to urgent physical action.
Your thoughts are interrupted when your boss suddenly calls you to his office.
For approximately four minutes, my neurotic thoughts are interrupted by a flight attendant whose incoherent ramblings dominate the PA system.
This thought was interrupted by a wail of grief from the other side of the room.
He would explain this mathematical wizardry, except that every few minutes his train of logical thought is interrupted by impulsive exclamations.
