Syrian Prime Minister Riyad Hijab has defected to Jordan, a Jordanian official source said on Monday, prompting Syria to announce he had been sacked and replaced by a caretaker premier.

"Hijab is in Jordan with his family," said the source, who did not want to be further identified.

Hijab's defection was one of the most high-profile desertions from President Bashar Al-Assad's political and military circles. On Sunday, Al Arabiya television reported a senior Syrian intelligence officer had also defected to Jordan.

Hijab, a Sunni Muslim from Syria's Sunni province of Deir Al-Zor, was also a ruling Baath Party apparatchik.

State television said Omar Ghalawanji, who was a deputy prime minister as well as minister for local administration, would lead a temporary caretaker government.

Assad had appointed Hijab, a former agriculture minister, as prime minister in June following a parliamentary election which came after more than a year of violent protests against Assad's rule.