Does the following passage contain a fused sentence error?

The letter said that they were not to be executed instead, they were to be sent to a distant prison.

Yes, the passage contains a fused sentence error. Two independent clauses, "The letter said that they were not to be executed" and "instead, they were to be sent to a distant prison," are combined without any punctuation or conjunction to separate them properly.

Yes, the passage contains a fused sentence error. In a fused sentence, two independent clauses (complete sentences) are joined together without appropriate punctuation or conjunction. In this case, "The letter said that they were not to be executed instead" and "they were to be sent to a distant prison" are two complete thoughts that are incorrectly merged together without appropriate punctuation or conjunction.