Video captures volcanic-created tornadoes after Indonesian eruption

According to the site, "the pyroclastic flow deposits red-hot material on the slope of the volcano. After a few minutes, air heated by the deposit establishes a convective regime and due to the speed of the rising air a series of small tornados are formed."

It's hard to tell just how how the volcanic flow is during daylight, so they've posted a nighttime video of the same volcano for reference (this one is sped up 5 times normal speed.)