The environmental campaign group Extinction Rebellion have broken into a coal mine set for expansion.
The group gained access to the Aberpergwm mine at around 4pm on Sunday.
Protestors could be seen climbing on buildings within the site, before a group staged a sit in.
Several members of the group have also chained themselves to a gate.
The Aberpergwm mine in Glyn Neath was granted a new license this week, giving it permission to extract another forty million tonnes of coal.
The Welsh Government has previously said the power to revoke any license is out of its hands, while the owners of the site say most of the coal will not be burned but used for water filtration and electric batteries instead.
The company has labelled the mine as the "only source of high-grade anthracite in Western Europe."
Also referred to as ‘hard coal', anthracite has the highest carbon content of all coal types. It has lower levels of sulphur and produces more heat and less smoke than other types of coal.
Protestors at the site say that the decision to mine more coal in Wales it at odds with the Welsh Government's declared climate emergency.
Around six police vehicles are in attendance at the site and the police response has been led by a local inspector.