An 18-year-old Tucson man arrested on suspicion of plotting terrorist attacks faces a new count after being indicted.

Mahin Khan was charged with terrorism, conspiracy to commit terrorism and conspiracy to commit misconduct involving weapons on Wednesday. Authorities released the indictment on Thursday.

They say Khan plotted an attack on a Motor Vehicle Division office in Maricopa County and that he made contact with an alleged member of a terrorist organization to seek weapons and instructions for a home-made bomb.

Court records do not list an attorney for Khan.

Authorities say Khan wrote in emails to the alleged member of the Pakistan Taliban that he was a supporter of the Islamic State group and was looking to carry out an attack.

He briefly attended a Tucson high school but left over disciplinary issues.