I don’t have source, but the government has planned sales for months to cover budget decifit and only 3 entities own enough stocks to make such sale and the other two just added more. And it would be extremely unlikely that they’d sell almost all of their holdings at once (or any, at this price point).
I can’t find any news either and it’s weird that such a daily volume went unnoticed, but I assume the news will come when they update the list of state owned stocks.