A: Soldiers dressed in civilian clothes, who were ordered into the street.
Most people have assumed that many of the thugs beating back protesters every day in Sanaa have been paid agents of the ruling party, but as members of the ruling party continue to deny this international reporters are forced to label them as "pro-government demonstrators (the pro-government is misleading) or pro-Salih demonstrators (more accurate).
This News Yemen piece (Ar.) pours some cold water on the official denials.
The story details the case of a villager it will only identify as "Khalid" for fear of government reprisals.
Well, Khalid was out with the protestors calling for the fall of Salih's regime and, as has become the norm over the past few days, there was a clash between these protestors and the thugs. In the middle of the group of thugs he saw someone he recognized: Muhammad a guy he knew from his home village.
In the middle of the clash, Khalid calls out: Muhammed you're a thug?"
Not only did he know Muhammad, but he knew that he was a soldier stationed at the Sawan Base (This is in Bani Hashish area outside of Sanaa.)
Later that night when they spoke on the phone this is what Muhammad told him: "we were forced to go out by a military order."