"These charges hammer home the point that terrorists and their supporters are not confined to the remote regions of some far away land but can grow and fester right here at home," George Holding, a US federal attorney, said.

'Terrorist support'

The seven men appeared in court in the city of Raleigh on Monday, charged with providing material support to terrorism. If convicted, they could face life in prison.

Court documents charged that Boyd, also known as "Saifullah", encouraged others to participate in terrorist activities.

"These people had broken away because their local mosque did not follow their vision of being a good Muslim," Holding said. "This is not an indictment of the entire Muslim community."

In 1991, Boyd and his brother were convicted of bank robbery in Pakistan - accused of carrying identification showing they belonged to the Hizb-i-Islami group in Afghanistan. Each was sentenced to have a foot and a hand cut off for the robbery, but the decision was later overturned.

Among the suspects were Boyd's sons, Zakariya, 20, and Dylan, 22. The others are Anes Subasic, 33, Mohammad Omar Aly Hassan, 22, and Ziyad Yaghi, 21. Hysen Sherifi, 24, a native of Kosovo and US immigrant was also charged in the case.

It is unclear how authorities learned of the activities, although court documents indicate that prosecutors will introduce evidence gathered under the Foreign Intelligence Surveillance Act.