It came as no big surprise when a crumbling oil town in western Kazakhstan stirred in protest last Sunday, 10 years after security forces there killed more than a dozen workers who had gone on strike over pay and poor conditions.

But it remains a mystery how peaceful protests over a rise in fuel prices last weekend in Zhanaozen, a grimy, Soviet-era settlement near the Caspian Sea, suddenly spread more than 1,000 miles across the full length of Central Asia’s largest country, turning the biggest and most prosperous Kazakh city into a war zone littered with dead bodies, burned buildings and incinerated cars.

The violence this week in Almaty, Kazakhstan’s former capital and still its business and cultural hub, shocked just about everyone — not only its leader, who, fortified by Russian troops, Friday ordered security forces to "fire without warning” to restore order, but also government critics who have long bridled at repression and rampant corruption in the oil-rich nation.