thousand of protesters in several cities today. crackdown on dissent continues despite thursday's call from others for regime change. senior white house foreign affairs correspondent goleta reports op what options are left with the administration. >> syrian security forces killed more than a dozen protesters a day after president obama and european leaders called for bashar assad to step down. amateur video refuted assad's claim that military and police operations had ended. -up officials say assad's forces may have committed crimes against humanity. state department spokeswoman victoria nulland says the u.s. not considering military intervention. >> that is not the preferred option for anybody. not in the first instance for syrians themselves. it's been very interesting to see them take the nonviolent route. >> u.s. official res ject comparisons between syria and libya, where nato forces are pushing muammar gaddafi from power under a u.n. mandate to