A Romanian court has blocked the expansion of the country's biggest coal mine.

NGO Bankwatch Romania, who challenged the Complexul Energetic Oltenia (CEO) energy company in the courts, welcomed the appeal's ruling in its favour.

"It's high time for Romania to develop a realistic strategy to ensure that polluting and expensive sources of energy, such as coal, are replaced with sustainable ones while at the same time making sure that employment is safeguarded in mining areas," Bankwatch, the largest network of grassroots environmental groups in central and eastern Europe, said in a statement.

"Romania is one of only seven EU countries left which have not set a coal phaseout date, but it won't be able to postpone this decision much longer. In this context, giving the green light to new coal mines only means deceiving locals and miners," it added.

During the two-year legal battle, Bankwatch argued that the expansion had initially been granted without properly consulting locals and that the environmental impact of such an expansion had not been assessed.

It also added that it would pollute the area, including underground water, and that endangered species would also be negatively impacted.

CEO wanted to expand Rosia's 1,450-hectare coal mine by a further 280 hectares, 235 of which are currently covered by forest which would have had to be cut off, according to Bankwatch.

In a statement to Euronews, CEO deplored that the court has not yet revealed why it sided with Bankwatch.

"Complexul Energetic Oltenia complies with all the environmental rules imposed by the EU, certified fact and by the two environmental expertise required by the court," it added.

In 2015, Romania had already achieved the European Union's renewable energy target for 2020.

Its main energy source back then was natural gas (29%), followed by oil (26%), renewables (19%), coal (17%), and nuclear (9%), according to scientists.