Authorities in New Hampshire arrested and charged two crew members of a Pearl Harbor-based nuclear submarine with beating a man unconscious and threatening a witness on a Portsmouth, N.H., street.

The victim, a 48-year-old man, was found badly beaten shortly before midnight. He remained in critical condition yesterday at Portsmouth Regional Hospital with a broken skull.

Gerald Smith, 22, and Sandy Portobanco, 23, assigned to the USS Greenville, were charged with first-degree assault and witness tampering. They were being held at the Rockingham County Jail on $200,000 bail.

The USS Greenville is at Portsmouth Naval Shipyard for extended maintenance, a Navy spokesman said.

Portsmouth police said Smith was driving a government van when he took offense to a comment the victim made. Smith and Portobanco confronted the victim and beat him, police said. They also allegedly threatened a witness before fleeing the scene.