COLUMBIA — The staff guarding a terrorist suspect could be in danger if he is allowed to watch television news about the wars in Iraq and Afghanistan, prosecutors said.

Ali al-Marri, a legal resident alien from Qatar, is the only enemy combatant held on U.S. soil. He was arrested in 2001 and has been held in solitary detention at the Charleston Naval Consolidated Brig for nearly five years.

His attorneys have said his isolation has affected his ability to assist in his defense and are asking that he be allowed unrestricted access to TV news and quicker processing of mail from relatives overseas.

In a 35-page filing Tuesday, prosecutors said they support a recommendation by a federal judge who wrote last month that al-Marri's attorneys had not proved their client's mental health would be permanently damaged without those perks.

They wrote that full access to news could encourage belligerence and hamper the government's ability to get information from al-Marri. Authorities said he was an al-Qaida agent living in America, researching poisonous gasses and plotting a cyberattack.

Attorney Jonathan Hafetz of the Brennan Center for Justice dismissed the government's contention that his client will become violent if he sees news on the war.

"He's never acted violently towards brig staff," Hafetz said. "The notion that allowing someone to watch CNN or Fox News would cause any threat is absurd."