Vietnamese consumers woke up on Friday to a 6.08 percent electricity price hike that authorities failed to announce until one day before it came into effect.

Power prices in the Southeast Asian country now average VND1,720.65 per kWh, excluding value-added tax, compared to the previous rate of VND1,622.01 per kWh, the Ministry of Industry and Trade announced late Thursday.

The ministry underlined in its announcement that the price hike had been backed by the prime minister, and was calculated after reviewing the production costs of EVN, the country’s power monopoly, in 2016.

The results of the review have been audited by both an independent unit and an inter-ministerial team, according to the ministry.

EVN’s total power production topped 159.79 billion kWh in 2016, with a transmission loss ratio of 7.57 percent, according to the state-run company’s financial report.

The electricity giant reported a power cost price of VND1,665.29 per kWh, and total production expenses of more than VND266.1 trillion (US$11.72 billion) the same year.

In the meantime, EVN posted only in VND265.51 trillion ($11.7 billion) in revenues from power, meaning the company racked up VND593.46 billion ($26.14 million) in losses.

However, the company’s income from other activities were enough to offset losses from its power generating and distributing business and enabled it to enjoy a healthy VND2.65 trillion ($116.74 million) in profits in 2016.

Members of the public question EVN’s choice to raise prices while it is operating at a gain.