The scale of the operation needed to smuggle Hijab and his relatives across the border to Jordan - Hijab's family and those of seven brothers and two sisters were all moved to safety - speaks volumes for difficulties facing potential defectors.

"Today I tell you there are 10 families, praise be to God, all of them are well, who have reached safety in a secure area and who are now in excellent health," Hijab's spokesman, Mohamed Atari, said in a broadcast on Al Jazeera television from Jordan.

"They and their children have reached a secure place," he said, giving no further details of how they escaped.

Others who have fled so far include soldiers, diplomats and politicians, but the fear of revenge against relatives left behind in Syria has prevented the stream of defections turning into a flood, defectors say.

Lieutenant-General Abu Furat al-Garabolsi, an army tank brigade commander, faced the same dilemma as all would-be defectors when he planned his desertion. If he left without his family, he would be abandoning them to almost certain death. But if his family made unusual trips that would attract suspicion.

"If they found out that an army soldier was sending his wife or children abroad, they knew it meant he was planning to defect," the 42-year-old told Reuters in Aleppo, where he now leads a group of fighters in the Saleheddine district.

"The punishment for that was going to be the execution of my family and anyone related to me."

Two months ago, taking advantage of the school summer holidays, he sent his family away. "The day I decided to defect, I was ordered to carry out a tank operation against the (rebel) Free Syrians," he said. "I just couldn't do it, so I escaped."

Even though his family were safe he, still paid a price. His former driver in the military called him a few days ago to say that his home in Qerdaha, where he served, had been burned to the ground as punishment for his defection.

"The house is replaceable but my heart is broken over the photographs of my girls," he said. "Every two months I would take them to get photographed and I'd display their photos around the house. Now I will never have those memories back."

BRUTAL TREATMENT

Hosam Hafez, a Syrian diplomat who defected last month from Syria's diplomatic mission in Armenia, said brutal treatment of defectors' families was a deterrent from early in the uprising.

"They killed most of the family of Hussein Harmoush, the first officer to defect. Dozens of people were killed," he said.

Since Harmoush defected a year ago, rebels say thousands of soldiers have joined their ranks, including more than 20 generals. But high level civilian defections have been rare.

Hafez said six or seven Syrian diplomats had defected so far despite foreign ministry efforts to restrict their movement, while others are still waiting to seize their chance.

"The policy of our ministry was to recall a big number of diplomats back to Syria," he said. "Usually we have 350 to 400 diplomats outside, now I guess we have much less than half this number in the missions outside."

Hafez, stationed in London when the uprising against Assad began in March last year, said he received threats from Assad supporters when he expressed concern about the crackdown on protests. He was transferred to Armenia until, around 10 days ago, he was able to flee.

"It was not easy at all," he said, without giving details.

For Prime Minister Hijab, surrounded by security, the operation would have been far more difficult. Atari said that after the Damascus bombing which killed four of Assad's top security officials three weeks ago, dozens of soldiers were assigned to watch the prime minister.

"Riyad was in a mosque and after the Friday prayers a colonel came to him, with 45 members of the Republican Guard, and he said 'We are here to protect you'," Atari said, adding that plans for his defection had been hatched two months ago.

Ahmed Ramadan, an executive member of the opposition Syrian National Council, said the SNC was in contact with more potential defectors.

"We're organising measures for them," he told Reuters, adding that a special team was working on ensuring their safety. "I have in front of me now a list of 15 political and diplomatic officials who have demanded to defect from the regime," he said.

"These measures are on three levels, including securing the safety of the person defecting, securing the safety of the family and relatives of the person defecting and (securing) the area the defected person will move to," he said.