President Bashar Assad appears to be following his father's example

Both were arrested last year after calling for greater political freedom in Syria.

Several other opposition figures are due to be tried on similar charges in the state security court.

Correspondents say the sentences given to Mr Seif and Mr Homsi have damaged hopes that President Bashar Assad would allow greater freedom after decades of his late father's authoritarian rule.

Mr Seif was also given another six-month sentence to run concurrently on charges of forming a secret society and organising illegal meetings.