(CNN) -- Lawyers for Boston Marathon bombing suspect Dzhokhar Tsarnaev accused the government of imposing unduly harsh restrictions on their client in a motion filed Wednesday.
Tsarnaev is "in near total isolation," is banned from praying with other inmates and is allowed out of his cell only to meet with lawyers or spend short periods in an outdoor enclosure, court documents said.
Massachusetts U.S. Attorney Carmen Ortiz asked the attorney general for these special administrative measures after Tsarnaev had been in prison for four months.
Ortiz said the restrictions are necessary as part of what prosecutors call Tsarnaev's "continued desire to incite others to engage in violent jihad," according to the August memorandum included in the court filing.
As evidence, prosecutors cite the 1,000 "unsolicited" letters the 19-year-old Chechnya-born American has received during his five-month incarceration. His lawyers say he has not responded to any of them.
Tsarnaev has been at the Fort Devens prison facility an hour outside Boston after a brief hospitalization for wounds incurred during his capture on April 19. Dzhokhar Tsarnaev and his brother, Tamerlan, spent days on a highly publicized run after the marathon bombing on April 15.
His lawyers, Miriam Conrad and Judy Clarke, argue in court papers that the measures create "obstacles" that have a "dramatic chilling effect on the defense team's ability to prepare a thorough and vigorous defense."
In their motion, Conrad and Clarke argue the measures "violate the First, Fifth and Sixth Amendments to the United States Constitution. The court therefore should declare that the SAMs are unlawful and order that they be vacated."
The restrictions are designed to limit the people with whom Tsarnaev is allowed to speak and what those people can then say to others. It also limits the kind of materials to which he has access. As an example, his lawyers said they were prevented from showing Tsarnaev family photos after prosecutors argued they were not specifically related to his defense. Prosecutors later relented.
Tsarnaev's lawyers accuse the government of trying to limit attorney-client interaction: "There is no basis whatsoever to suspect that appointed attorneys and those assisting them would intentionally pass dangerous communications to others."
His lawyers also said Tsarnaev has done nothing during his incarceration to warrant such restrictions or to suggest he is dangerous, nor is there evidence the attack was "directed by others still at large or that Mr. Tsarnaev ever had operational authority to direct the activities of others" to whom he may want to communicate.
Special administrative measures are typically used in terrorism cases and other high-profile cases when authorities contend "there is a substantial risk that a prisoner's communications or contacts with persons could result in death or serious bodily injury to persons," according to court documents.
Tsarnaev is charged with 30 federal counts stemming from the attack, during which three people were killed and more than 250 were injured after a pair of home-made bombs exploded moments apart near the finish line of the Boston Marathon. A Massachusetts Institute of Technology police officer was killed three days later, triggering the massive manhunt that led to Tsarnaev's capture. His brother was shot and killed by police during the manhunt.
Tsarnaev has pleaded not guilty to all charges.
CNN's Lawrence Crook III contributed to this report.