A Pennsylvania man already accused of trying to assist the Islamic State group was charged Wednesday after federal authorities said he tweeted out the names and addresses of military personnel with threats of violence.

Jalil Ibn Ameer Aziz, 19, of Harrisburg, was charged with solicitation to commit a crime of violence and transmitting a communication containing a threat to injure.

Prosecutors allege he tweeted the names, addresses, photographs and military branches of about 100 service members with statements such as "kill them in their own lands, behead them in their own homes, stab them to death as they walk their street thinking that they are safe" and "Identities of Military personnel that bombed Muslims. Find them, Kill them!"

Assistant federal public defender Thomas Thornton said the charges involve "a 19-year-old kid tweeting and retweeting" from his bedroom. He also said the conduct alleged was before his client's arrest last year.

Aziz pleaded not guilty in December to trying to help a group designated by the U.S. government as a foreign terrorist organization. Prosecutors said Aziz used Twitter to spread Islamic State propaganda and had concealed a bag loaded with ammunition behind a dryer in his home.

Authorities allege in a criminal complaint that he used 57 different Twitter accounts — all traced to the home he shares with his parents — to advocate violence, encourage people to fund jihadist groups and express a desire to travel to territory controlled by the Islamic State group.

A defense attorney earlier called the bag as a backpack that contained nothing illegal and said there were no guns in the home when Aziz, who has no criminal history, was arrested.