LONDON — A former Guantanamo Bay detainee and human rights activist was arraigned Saturday in a London court on charges of promoting terrorism in Syria.

Moazzam Begg, a prominent defender of terrorist suspects' rights since his return to Britain in 2005, denied charges that he provided terrorist training and funded overseas terrorism. The 45-year-old was ordered held in custody until his next court appearance March 14.

Begg was arrested Tuesday along with three others in Birmingham, Britain's second-largest city. One, 44-year-old Gerrie Tahari, appeared alongside him in court Saturday and denied a charge of aiding overseas terrorism.

Detectives still are questioning the two others, among them Tahari's 20-year-old son.

Begg was arrested in Pakistan in 2002 as an "enemy combatant." He was held by U.S. forces in Afghanistan and sent a year later to the U.S.-run prison camp in Cuba. He was released without charge in 2005 and now helps to direct a London-based lobbying group called Cage.

Cage branded the charges against Begg as an attempt to silence him.