The protests began because 30% of all government jobs are set aside for the descendants of “freedom fighter” — an estimated 3% of the population. As is so ofter the case, especially when Muslims are involved, things got out of hand. Government troops used live ammo on the protesters and events spiraled out of control until Sheikh Hasina hitched up her sari and fled to India. As Wikipedia puts it, her departure was followed by “joyous celebration and violence.” Mohammed Younus has been appointed interim PM.
this is what US wanted to counter the influence of China and Russia, shortly someone that the government want will be installed
So it's kind of strange that they're in a crisis now.