OTTAWA, Sept 27: Canadian authorities have dropped what they called “security concerns” against six more Muslim suspects, including a student-pilot who was allegedly scouting around the Pickering nuclear plant near Toronto.

Twenty-one people, 20 Pakistanis and an Indian, were arrested in Toronto last month with police suspecting their links with Al Qaeda. Three Pakistanis were cleared of terrorist charges earlier this week but some of them may be tried for violation of immigration laws.

An immigration tribunal released the pilot, Anwar-ur-Rehman Mohammed, 31, on a $25,000 bail after a government counsel, Stephanie MacKay, announced that security allegations had been dropped against the native of Hyderabad, India.

Fahim Kayani, a Pakistani, was also released on a $2,000 performance bond, while fellow countryman Jahan Sawnhey was let go on a $5,000 cash bond.

Anwar-ur-Rehman, a pharmacist whose wife and child remain in India, was the key suspect in the probe, with his Pickering overflights and incomplete pilot training conjuring up comparisons to 9/11 terrorist plotters.

Mr Rehman arrived in Canada three years ago in hopes of obtaining a commercial pilot’s licence. His flight path on several occasions, investigators said, took him over the Pickering plant.