A well-written article on this from a Russian point of view:

https://www.rt.com/russia/545219-kazakhstan-protests-nationalists-security/

Cars there run on liquified natural gas (LNG). The government has been subsidizing the cost, but they stopped doing that, and the price doubled overnight.

Roman Yuneman, a Russian political figure who spent the first 18 years of his life in Kazakhstan, agrees with Mendkovich that local nationalists are the basis of the protest movement. “It’s not the liberals, or hipsters, who are protesting – it’s the nationalists and patriots. That’s why you can see so many of them holding the national flag, and some are even singing Kazakhstan’s anthem,” he said. Yuneman points out that today’s protests have the largest scale in the history of independent Kazakhstan.

He believes that other factors at play here are the prolonged economic crisis and the Covid-19 pandemic that only aggravated the situation.

The unrest, however, appears to be mostly spontaneous and uncontrolled. It seems there are no leaders to organize the crowds, nor has any political party spearheaded the protest movement yet. The government simply does not know who to negotiate with, while the demonstrators are gaining control of many of Kazakhstan’s public buildings, as well as storming and destroying the offices of the Nur Otan ruling political party and national television channels.