A pan-Arab TV station says the general who heads Syria's military police has defected and joined the uprising against president Bashar Assad.
Major General Abdul-Aziz Jassem al-Shallal has appeared in a video aired on Al Arabiya TV saying he is joining "the people's revolution".
In the video aired late Tuesday, Maj Gen al-Shallal said the army deviated from its mission of protecting the nation and became "a gang for killing and destruction".
Dozens of generals have defected since Syria's crisis began in March 2011 but Maj Gen al-Shallal is one of the most senior and held a top post at the time that he left. In July, Manaf Tlass, a Syrian general, was the first member of Assad's inner circle to break ranks and join the opposition.
Maj Gen Al-Shallal's defection comes as military pressure builds on the regime, with government bases falling to rebel assault near the capital Damascus and elsewhere across the country. The Britain-based Syrian Observatory for Human Rights said government shelling in the north-eastern province of Raqqa killed at least 20 people, including women and children.
Maj Gen Al-Shallal in the video accused the military of "destroying cities and villages and committing massacres against our innocent people who came out to demand freedom".
Thousands of Syrian soldiers have defected over the past 21 months and many of them are now fighting against government forces. Many have cited attacks on civilians as the reason they switched sides.
The Observatory said the shelling in an agricultural area of Raqqa province near the village of Qahtaniyeh killed 20, including eight children, three women and nine others.
An amateur video showed the bodies of a dozen people including children lying in a row inside a room. Some of them had blood on their clothes, while weeping could be heard in the background. The videos appeared genuine and corresponded to other reporting on the events depicted.
Also today activists said rebels were attacking the Wadi Deif military base in the northern province of Idlib. The base, which is near the strategic town of Maaret al-Numan, has been under siege for weeks.