A 21-year-old Florida man accused of conspiring to aid al-Qaida and traveling to the Middle East to join terrorist groups has been sentenced to 20 years in prison.

The U.S. Attorney's Office in Jacksonville reports that Shelton Thomas Bell was sentenced Wednesday. He pleaded guilty last year to conspiracy to provide material support to terrorists and attempting to provide material support to terrorists.

Authorities say Bell planned to join Ansar Al-Sharia, which is an alias for al-Qaida. The group has taken responsibility for attacks on Yemeni forces, including a suicide bombing during a parade in May 2012. That attack killed more than 100 Yemeni soldiers.

Investigators say Bell participated in physical, firearm and other training in Florida to prepare for armed conflict.