Millions of dead fish stretched out over 200 kilometers of central Vietnamese beaches are posing the biggest test so far for the new government.

The Communist administration led by Prime Minister Nguyen Xuan Phuc has been criticized on social media for a lack of transparency and slow response, with thousands protesting Sunday in major cities and provincial areas. The government says it doesn’t know why the wild and farmed fish were found dead on the coast of four provinces from April 6 to April 18.

The phenomenon “caused economic and environmental damage, hurt the fishery industry, and particularly resulted in puzzled sentiment among citizens,” it said in a statement April 28. READ MORE